Investor-State Arbitration: Treaty Protections, Jurisdiction, and the Enforcement of Awards Against States

Document type: Article Practice area: Litigation — International Arbitration Jurisdiction: International, with United States enforcement law Last reviewed: 5 September 2026

Arbitration without a contract

A company builds a power plant in a foreign country under a licence from the state. Five years later the government revokes the licence, seizes the plant, and offers no compensation.

The company has no arbitration agreement with the state. It never negotiated one. And yet it can commence arbitration against the state, before a tribunal seated outside that country, applying international law rather than the state's own.

The mechanism is a treaty — a bilateral investment treaty between the investor's home state and the host state, or a multilateral investment agreement, or the investment chapter of a trade agreement. The treaty contains a standing offer by each state to arbitrate disputes with investors of the other, and the investor accepts that offer by filing a claim.

This is the structural feature that makes investor-state arbitration distinctive. The state consented in advance, to a class of counterparties it could not identify, in an instrument negotiated with another state. The investor is a third-party beneficiary who becomes a party by electing to be one.

And the consequences are substantial. The investor escapes the host state's courts, which may be neither independent nor sympathetic. It obtains a tribunal applying treaty standards developed across hundreds of awards. And it obtains an award enforceable, in principle, in most of the world.

The system has critics, and their arguments — that it privileges foreign investors over domestic ones, that it constrains legitimate regulation, that the tribunals are inconsistent, and that the arbitrators are drawn from a small pool with repeat appointments — are serious and have produced real reform. Several states have terminated treaties, others have renegotiated them with narrower protections and carve-outs for public welfare regulation, and one significant treaty regime has been unwound as among certain member states. A practitioner advising today must check what the applicable instrument currently provides, because the landscape has moved.

The jurisdictional requirements

Most investor-state claims that fail, fail on jurisdiction. The tribunal must be satisfied of each of the following, and a state facing a claim will contest every one it can.

An investor of the other contracting state

The claimant must be a national of a state party to the treaty. For a natural person, nationality; for a company, the test in the treaty — usually incorporation, sometimes seat, sometimes control.

Treaty shopping. Because protection depends on nationality, investors structure their holdings through jurisdictions with favourable treaties. This is generally permissible if done before a dispute arises, and generally impermissible if done afterwards — a restructuring undertaken to acquire protection for an existing dispute is an abuse of process, and tribunals have declined jurisdiction on that basis.

The practical instruction: structure early. An investment held through a holding company in a state with a good treaty network is protected; the same investment restructured after the state's first adverse measure is not.

A protected investment

The treaty defines "investment," usually broadly — every kind of asset, including shares, contractual rights, concessions, and intellectual property.

But breadth is not unlimited. Under the ICSID Convention, tribunals have developed criteria for what constitutes an investment for the purposes of the Convention itself, commonly requiring a contribution, a certain duration, an element of risk, and — in some formulations — a contribution to the host state's development. A single sale of goods is not an investment, however large.

Legality. Many treaties protect investments made "in accordance with the law" of the host state. An investment obtained through corruption, or in breach of local law, may fall outside protection entirely, and states raise this defence with increasing frequency and success.

Consent, and the conditions attached to it

The state's offer to arbitrate is subject to whatever conditions the treaty attaches, and those conditions are jurisdictional.

Cooling-off periods. Most treaties require a period — commonly six months — of attempted amicable settlement after a notice of dispute, before arbitration may be commenced. This is a genuine requirement, and claims have been dismissed for non-compliance.

Local litigation requirements. Some treaties require the investor to litigate in the host state's courts for a period — commonly eighteen months — before arbitrating.

BG Group plc v. Republic of Argentina, 572 U.S. 25 (2014) addressed exactly this. The treaty required eighteen months of local litigation. The investor did not comply, arbitrated anyway, and won. Argentina sought to vacate on the ground that the tribunal lacked jurisdiction.

The Supreme Court held that the local litigation requirement was a procedural precondition to arbitration, presumptively for the arbitrators to interpret and apply, rather than a condition on the state's consent for a court to decide de novo. The award stood.

BG Group is significant beyond its facts: it treats the treaty's arbitration provisions as an ordinary contract for these purposes, and it applies the familiar presumption that procedural preconditions are for arbitrators.

Fork-in-the-road provisions. Some treaties provide that an investor choosing local courts or arbitration is bound by the choice. The election is irrevocable, and an investor that commences local proceedings may forfeit treaty arbitration.

Denial of benefits clauses. Many treaties permit a state to deny protection to a company that has no substantial business activity in its state of incorporation and is controlled by nationals of a third state, or of the host state itself. The timing of invocation is contested — whether a state may deny benefits after a claim is filed — and tribunals have divided.

The temporal requirement

The treaty must have been in force when the measures complained of occurred, and the investment must have existed. Measures predating the treaty's entry into force are generally outside jurisdiction, though a continuing breach may be actionable.

The substantive protections

Fair and equitable treatment

The most invoked and most contested standard, and the basis of most successful claims.

Its content has been developed across hundreds of awards, and the recurring elements are:

Protection of legitimate expectations. Where the state made specific representations on which the investor relied in making its investment, and then acted contrary to them
Transparency and consistency in the regulatory framework
Due process in administrative and judicial proceedings, and freedom from denial of justice
Freedom from arbitrary, discriminatory, or abusive treatment
Good faith

The central tension is regulatory change. A state that changes its law — raising taxes, altering a tariff, tightening environmental standards — has not thereby breached the standard. Investors are not entitled to a frozen legal framework. But a state that made specific commitments to an investor, induced the investment on that basis, and then reversed them may have.

Where treaties have been renegotiated, the fair and equitable treatment standard is frequently narrowed — tied expressly to the minimum standard of treatment under customary international law, with a statement that a breach of another provision or of the investor's expectations does not itself establish a breach.

Expropriation

Every investment treaty prohibits expropriation without compensation.

Direct expropriation — formal taking of title — is rare and easy to identify.

Indirect expropriation is the litigated question: measures that, without formal taking, substantially deprive the investor of the value or control of its investment.

The factors tribunals apply:

The economic impact — has the investment been substantially deprived of value?
Interference with distinct, reasonable investment-backed expectations
The character of the measure — is it a bona fide, non-discriminatory regulation in the public interest?
Duration — a temporary measure is less likely to be expropriatory

The police powers doctrine. Non-discriminatory regulation adopted in good faith for a legitimate public purpose — health, safety, environment, taxation — is generally not compensable expropriation, even if it destroys the investment's value. Modern treaties state this expressly, frequently with a carve-out for measures that are "rare" or "extreme."

Compensation, where expropriation is established, is generally the fair market value of the investment immediately before the taking, with interest.

National treatment and most favoured nation

National treatment: treatment no less favourable than that accorded to the state's own investors in like circumstances.

Most favoured nation: treatment no less favourable than that accorded to investors of any third state.

The MFN clause has generated the field's most difficult question: can an investor use an MFN clause to import procedural provisions from another treaty — a shorter cooling-off period, the absence of a local litigation requirement, a broader dispute resolution clause?

Tribunals have divided sharply. Some have permitted importation of dispute resolution provisions; others have held that MFN applies to substantive treatment only, on the reasoning that the state's consent to arbitration is a specific bargain not subject to importation. The answer depends on the treaty's language and on the tribunal, and it is one of the field's genuine inconsistencies.

Newer treaties resolve it expressly, usually by providing that MFN does not extend to dispute resolution procedures.

Full protection and security

An obligation of due diligence to protect the investment from physical harm — by state organs, and by third parties where the state failed to exercise vigilance. Some tribunals have extended it to legal security, protecting the stability of the legal framework, though this reading is contested and newer treaties frequently limit it to physical security.

The umbrella clause

A provision by which the state undertakes to observe any obligation it has entered into with respect to an investment.

Its effect, where it appears, is to elevate contract breaches into treaty breaches. A state that breaches a concession agreement with an investor may thereby breach the treaty, giving the investor treaty arbitration for what would otherwise be a contract claim in local courts.

Tribunals have divided on the scope: whether it covers all contractual obligations or only those the state assumed in a sovereign capacity; whether it overrides a contractual forum selection clause; and whether it requires the claim to be brought by the contract counterparty. A contract with a state entity containing an exclusive local forum clause, combined with a treaty containing an umbrella clause, produces a genuinely difficult analysis.

Two systems: ICSID and everything else

ICSID

The International Centre for Settlement of Investment Disputes, established by the ICSID Convention, provides a self-contained system.

Its distinctive features:

Jurisdiction requires a legal dispute arising directly out of an investment, between a Contracting State and a national of another Contracting State, with written consent
Awards are binding and are not subject to review by national courts — no set-aside proceedings at a seat, because there is no seat in the ordinary sense
Annulment is available, but only before an ad hoc committee appointed under the Convention, and only on five grounds: improper constitution of the tribunal; manifest excess of powers; corruption of a member; serious departure from a fundamental rule of procedure; and failure to state reasons
Recognition and enforcement are automatic among Contracting States: each must recognize an award as binding and enforce the pecuniary obligations as if it were a final judgment of its own courts
But execution remains subject to the state's own law on sovereign immunity from execution, which is the limitation that matters

The annulment grounds are narrow and are not an appeal. Committees have annulled awards for manifest excess of powers and for failure to state reasons, and the jurisprudence on how narrowly to read those grounds has itself been inconsistent.

Non-ICSID arbitration

Where ICSID is unavailable — because a state is not a Contracting State, or the treaty provides otherwise — arbitration proceeds under ad hoc rules or institutional rules, seated in a chosen jurisdiction.

The consequences of a seat:

The seat's courts have supervisory jurisdiction, including set-aside
The award is enforced under the New York Convention, implemented in the United States at 9 U.S.C. § 201 and following, with recognition and enforcement under 9 U.S.C. § 207
The grounds for refusing enforcement are the Convention's, including public policy

Choosing between them. ICSID offers insulation from national court review and automatic recognition. Non-ICSID offers a seat whose courts may be more predictable and a Convention enforcement regime that is well developed. Where the treaty offers a choice, the decision turns on the investor's assessment of annulment risk versus set-aside risk, and on where enforcement will be sought.

Enforcement against a state

Winning is not collecting. This is the field's defining practical problem.

Immunity from jurisdiction

In the United States, the Foreign Sovereign Immunities Act provides that a foreign state is immune from jurisdiction except as the Act provides. The relevant exceptions, at 28 U.S.C. § 1605, include:

Waiver, express or implied
Commercial activity — an action based on commercial activity carried on in the United States, or an act performed in the United States in connection with commercial activity elsewhere, or an act outside the United States in connection with commercial activity elsewhere that causes a direct effect in the United States
The arbitration exception, which removes immunity in an action to confirm an award made pursuant to an agreement to arbitrate, where the award is or may be governed by a treaty in force in the United States calling for recognition and enforcement — which is how New York Convention awards against states are confirmed
Expropriation in violation of international law, where the property or its proceeds is present in the United States in connection with commercial activity

Republic of Argentina v. Weltover, Inc., 504 U.S. 607 (1992) construed the commercial activity exception, holding that a state's issuance of bonds was commercial activity — the question is the nature of the act, not its purpose, and a state acting as a private player in the market is engaged in commercial activity.

Bolivarian Republic of Venezuela v. Helmerich & Payne International Drilling Co., 581 U.S. 170 (2017) addressed the expropriation exception's pleading standard, holding that a party must make out a legally valid claim that the rights in property taken were taken in violation of international law — not merely a non-frivolous argument. This raised the bar materially.

Immunity from execution — the harder problem

Immunity from jurisdiction and immunity from execution are separate. A judgment confirming an award does not entitle the creditor to seize any state asset it can find.

Under 28 U.S.C. § 1610, property of a foreign state in the United States is immune from attachment and execution except in enumerated circumstances, principally where the property is used for a commercial activity in the United States and one of several conditions is met — including that the judgment relates to an arbitral award, or that the state has waived immunity from execution.

The practical consequences:

Embassy and consular property is immune, as is military property
Central bank assets held for the bank's own account enjoy separate and strong protection
Property must be in the United States and used for commercial activity here — a state's assets abroad are outside the statute's execution provisions
A waiver of immunity from jurisdiction is not a waiver of immunity from execution. They must be waived separately, and investors negotiating with states should seek both

Rubin v. Islamic Republic of Iran, 583 U.S. 202 (2018) confirmed the strictness of the framework, holding that a provision permitting execution against certain assets did not itself strip immunity absent satisfaction of the statute's requirements. Property does not become executable merely because the judgment creditor has a valid judgment.

Discovery in aid of execution

Republic of Argentina v. NML Capital, Ltd., 134 S. Ct. 2250 (2014) held that the Foreign Sovereign Immunities Act does not limit discovery in aid of execution of a judgment against a foreign state. A judgment creditor may obtain discovery of a state's assets worldwide, from third parties such as banks, even as to assets that would themselves be immune from execution.

This is a powerful tool. It permits the creditor to map the state's assets globally and to pursue enforcement wherever the assets are and wherever the local law permits.

Enforcement in practice

The realistic sequence:

Confirm the award in a jurisdiction with a nexus and a favourable regime
Take discovery in aid of execution, using NML to map assets worldwide
Identify commercial assets — state-owned enterprise property, receivables, aircraft, vessels, bank accounts used commercially
Enforce in multiple jurisdictions, choosing those whose immunity rules are most favourable
Consider attaching receivables owed to the state by third parties
Consider the separate entity problem: assets of a state-owned enterprise are generally not the state's, unless the entity is an alter ego or the corporate form is being used to work a fraud or injustice
Negotiate. Most awards against states are settled, at a discount, because full enforcement is slow and uncertain

And consider political risk insurance in advance. For an investment in a jurisdiction with meaningful expropriation risk, a policy from a national export credit agency or a multilateral guarantee agency pays without requiring enforcement against the state, and the insurer then pursues the state through its own channels. This is frequently a better answer than a treaty claim.

Chevron Corp. v. Republic of Ecuador, 795 F.3d 200 (D.C. Cir. 2015) illustrates the jurisdictional analysis in an action to confirm a treaty award against a state, addressing the arbitration exception and the standard for establishing that an arbitration agreement exists where consent arises from a treaty.

Structuring an investment for treaty protection

Because protection depends on nationality and on the shape of the holding, the most valuable work in this field is done before the investment is made, not after a dispute arises.

Step 1 — Map the treaty network. For the target jurisdiction, identify every investment treaty in force and what each provides. They differ materially: some contain umbrella clauses and some do not; some require local litigation and some do not; some permit MFN importation of procedure and some expressly exclude it; some contain broad public welfare carve-outs and some are silent.

Step 2 — Choose the holding jurisdiction. A jurisdiction with a favourable treaty with the host state, a stable legal system, and — critically — the ability to give the holding company genuine substance.

Step 3 — Give the holding company substance. This is where structures fail. A denial of benefits clause permits the host state to deny protection to a company with no substantial business activity in its state of incorporation. Substance means: an office, employees, a board that meets there, decisions taken there, accounts and tax residence there, and a genuine role in the group. A nameplate company on a service provider's letterhead is not substance, and states raise the point.

Step 4 — Structure before the dispute. Restructuring to acquire protection after a state's adverse measure — or after it is foreseeable — is an abuse of process, and tribunals have declined jurisdiction on that basis. The line is when the dispute became foreseeable, which is earlier than when it crystallized.

Step 5 — Document the investment's legality. Permits, approvals, and the process by which they were obtained, retained contemporaneously. The illegality and corruption defences are raised in most modern cases, and a clean, documented permitting history is the answer.

Step 6 — Negotiate contractual protections alongside. Where the investment is made under a concession or a contract with the state:

A stabilization clause, freezing the fiscal and regulatory framework or requiring compensation for adverse change — this is what converts a weak legitimate-expectations argument into a strong one
An arbitration clause in the contract itself, seated outside the host state
A waiver of sovereign immunity from jurisdiction and, separately, from execution. These are distinct and must be waived separately
Choice of law other than the host state's, or the host state's law supplemented by international law

Step 7 — Buy political risk insurance. For investments of meaningful size in jurisdictions with real expropriation or contract-repudiation risk, a policy from a national export credit agency or a multilateral guarantee agency pays without requiring enforcement against the state. The premium is modest against the alternative, and the insurer's involvement is itself a deterrent — states are more reluctant to expropriate where a multilateral institution will pursue them.

The synthesis. Treaty protection is a fallback, not a plan. The plan is contractual protection, a properly structured holding, and insurance, with the treaty claim available if all of that fails.

A worked example: the Ostrowska claim

The investment. Karelia Renewables, a Dutch holding company owned by a Polish family, invests €180 million in a wind farm in a fictional state, Verania, under a twenty-year concession with a fixed feed-in tariff. Verania and the Netherlands have a bilateral investment treaty containing fair and equitable treatment, expropriation, MFN, and an umbrella clause, with ICSID arbitration, a six-month cooling-off period, and no local litigation requirement.

Year four. Verania, facing a fiscal crisis, enacts a law reducing feed-in tariffs for all renewable generators by 40%, retroactively. Karelia's project becomes marginally cash-flow negative.

Year five. The regulator revokes Karelia's grid connection permit on grounds Karelia says are pretextual, and the project stops generating.

The analysis

Jurisdiction.

Investor of the other state? Karelia is incorporated in the Netherlands. Verania will argue denial of benefits — that Karelia has no substantial business in the Netherlands and is controlled by Polish nationals. The outcome depends on the treaty's wording and on whether Karelia has genuine substance in the Netherlands, which is why holding structures should have real activity rather than a nameplate.
Protected investment? Yes — a long-term capital contribution with risk.
Legality? Verania will examine the permitting history for irregularities. The corruption and illegality defences are raised in most modern cases, and an investment obtained through improper payments falls outside protection.
Cooling-off? Karelia must serve a notice of dispute and wait six months. This is jurisdictional, and skipping it risks dismissal.
Temporal? The treaty was in force; the measures postdate it.

Merits.

The tariff reduction. This is the harder claim. A state may change its regulatory framework, and a general, non-discriminatory measure applying to all generators in a fiscal crisis is the paradigm of legitimate regulation. Karelia's argument rests on legitimate expectations: was there a specific commitment, in the concession or in representations made to induce the investment, that the tariff would be maintained? A stabilization clause in the concession would be decisive; a general statement of policy would not.

The permit revocation. The stronger claim. If the grounds were pretextual and the process denied due process, this is arbitrary and discriminatory treatment, and — because it destroyed the investment's value — potentially indirect expropriation. Verania will invoke the police powers doctrine and argue the revocation was a bona fide regulatory act; Karelia will point to the timing, the process, and any evidence of motive.

The umbrella clause. If the concession contained a tariff commitment, the umbrella clause may convert Verania's breach of that commitment into a treaty breach — subject to the contested questions about the clause's scope and about any exclusive forum clause in the concession.

MFN. Karelia may seek to import a more favourable substantive standard from another Verania treaty. Whether it may import procedural provisions is the contested question, and here it does not need to.

The procedure

Month 0. Karelia serves a notice of dispute describing the measures, the treaty provisions breached, and the relief sought, and proposing consultations.

Months 0–6. The cooling-off period. Genuine negotiation, not a formality — a meaningful proportion of disputes settle here, and a state facing a well-documented claim before it has spent on defence is at its most receptive.

Month 7. Request for arbitration filed with ICSID, registered by the Secretary-General.

Months 8–12. Tribunal constituted: one arbitrator appointed by each party, the president by agreement or by the Centre. Arbitrator selection is the single most consequential decision in the case.

Months 12–18. Verania files preliminary objections — denial of benefits, illegality, and that the tariff measure is a non-compensable regulatory act. The tribunal bifurcates, hearing jurisdiction first.

Months 18–36. Merits: memorials, documentary evidence, witness statements, expert reports on quantum, and a hearing.

Quantum. Karelia claims fair market value of €210 million plus interest. Verania argues the project was uneconomic in any event and that the discount rate should reflect country risk. Quantum is decided by competing valuation experts and is where most of the money is, and tribunals frequently award substantially less than claimed.

Month 42. Award: Verania liable for the permit revocation as an unlawful expropriation; the tariff reduction held to be a legitimate regulatory measure. Damages of €118 million plus interest.

The enforcement

Verania does not pay.

ICSID annulment. Verania applies, alleging manifest excess of powers and failure to state reasons. This stays enforcement pending decision — a delay of eighteen months to two years. The committee dismisses the application.

Confirmation. Karelia seeks recognition in the United States. Because the award is an ICSID award, the Convention requires recognition and enforcement of the pecuniary obligations as if it were a final judgment of a US court. Jurisdiction over Verania rests on the arbitration exception to sovereign immunity.

Execution. Here the difficulty begins. Karelia must find property of Verania in the United States used for commercial activity. Its embassy is immune. Its central bank reserves are immune. It identifies: a commercial office building owned by a Verania trade agency; receivables owed by a US commodities buyer to Verania's state oil company; and an aircraft used by a state airline.

The office building may be reachable if used for commercial activity.
The oil company receivables raise the separate entity problem: the state oil company is a distinct juridical entity, and its assets are presumptively not the state's. Karelia must establish alter ego or that respecting the form would work a fraud or injustice — a difficult showing.
The aircraft raises the same issue plus practical difficulties of attachment.

Discovery. Karelia uses NML to obtain worldwide discovery of Verania's assets from correspondent banks, mapping accounts and flows across jurisdictions, and then enforces in three other countries whose immunity regimes are more favourable.

Resolution. After three years of enforcement proceedings across four jurisdictions, Verania settles for €71 million, payable over four years.

The economics. Karelia recovered roughly 60% of its award, eight years after the permit revocation, having spent perhaps €14 million on the arbitration and the enforcement. That is a reasonably successful investor-state claim.

And the counterfactual. Had Karelia obtained political risk insurance covering expropriation and breach of contract at the outset, it would have been paid within eighteen months of the revocation, and the insurer would have pursued Verania. For an investment of this size in a jurisdiction of this risk profile, the insurance was the better answer, and the treaty claim was the fallback.

The state's defence

Advising a state is a distinct practice, and the defence has its own architecture.

Jurisdiction first, and comprehensively. Most successful defences end the case before the merits. Raise every available objection: nationality and denial of benefits; whether the claimant's interest is a protected investment; legality and corruption; the cooling-off and any local litigation requirement; fork-in-the-road; temporal scope; and the scope of consent. Seek bifurcation, so that jurisdiction is decided before the expense of a merits phase.

The regulatory defence. Frame the challenged measure as general, non-discriminatory regulation adopted in good faith in the public interest. The police powers doctrine, the absence of any specific commitment to the investor, and the state's sovereign right to regulate are the core of the argument. Assemble the contemporaneous record showing the measure's genesis, its application to domestic and foreign investors alike, and the public purpose it served.

Attack legitimate expectations. The investor must show a specific commitment on which it relied. General statements of policy, a favourable regulatory environment, and market expectations do not suffice. Was there a stabilization clause? A written assurance? A representation by an official with authority? If not, the claim is that the investor is entitled to a frozen legal framework, which no tribunal accepts as such.

Contest quantum aggressively. Awards are frequently a fraction of claims, and quantum is where the money is. Challenge: the valuation methodology; the discount rate and whether it adequately reflects country and project risk; the projections and whether they were achievable; the causation between the measure and the loss; and whether the investment was viable in any event.

The corruption and illegality defence has become central. Where there is evidence that the investment was procured improperly, the defence goes to jurisdiction and can end the case entirely. Investigate the permitting history, and consider whether a domestic investigation should run in parallel.

Consider counterclaims. Some treaties and some tribunals permit a state to counterclaim — for environmental damage, for tax obligations, for breach of the investor's own commitments. This is a developing area and the availability depends on the treaty's language and the tribunal's view of its jurisdiction.

Manage the political dimension. Investor-state claims are public, and adverse awards are politically costly. The state's counsel should coordinate with government communications from the outset, and should give realistic advice about the prospects rather than the advice the client wants.

And consider settlement seriously and early. A state facing a strong claim will do better settling in the cooling-off period than after a merits hearing. The obstacle is usually political rather than legal — no official wants to authorize a payment to a foreign investor — and counsel's job includes explaining that the alternative is a larger payment later, publicly, following an adverse award.

The system under reform

Practitioners should understand where the field is moving, because the instrument governing a particular investment may look very different from the classic template.

Treaty termination and renegotiation. A number of states have terminated bilateral investment treaties or allowed them to lapse; others have adopted new model treaties with substantially narrower protections. The practitioner's first step is to confirm what is actually in force, including whether a terminated treaty's sunset clause still protects existing investments.

Narrowed substantive standards. Newer treaties commonly: tie fair and equitable treatment expressly to the customary international law minimum standard; state that a breach of another provision or of an investor's expectations does not itself establish a breach; annex an interpretation of indirect expropriation confirming that non-discriminatory public welfare regulation is not compensable except in rare circumstances; exclude MFN from dispute resolution procedures; and add carve-outs for taxation, public health, prudential financial measures, and national security.

Procedural reform. Transparency rules requiring publication of pleadings, open hearings, and provision for amicus submissions have become common, reversing the confidentiality that characterized the earlier system. Codes of conduct for arbitrators address repeat appointments and dual roles. Some instruments provide for an appellate mechanism or for a standing tribunal rather than party-appointed arbitrators.

Third-party funding disclosure is increasingly required, and tribunals have ordered security for costs where a funded claimant might be unable to satisfy an adverse award.

Regional developments. One significant regional regime has been unwound as among certain member states following a determination that intra-regional treaty arbitration was incompatible with the region's own legal order, which has left a substantial body of pending and threatened claims in an uncertain position and has driven investors toward alternative structures.

What this means practically:

Do not advise from a template. Read the instrument.
Check whether the treaty is still in force, and whether a sunset clause applies.
Check the carve-outs, which may exclude precisely the measure at issue.
Check whether MFN reaches procedure, because newer treaties say it does not.
Assume transparency. Pleadings may be published, and the case will be publicly known.
Structure for the treaty that exists, not for the one the textbooks describe.

Quick reference

The mechanism. A treaty between two states contains a standing offer by each to arbitrate with investors of the other. The investor accepts by filing. No contract between investor and state is required.

Jurisdiction decides most cases. Nationality and denial of benefits; whether the asset is a protected investment; legality and corruption; cooling-off periods and local litigation requirements; fork-in-the-road; temporal scope. Contest every one, and seek bifurcation.

BG Group treats local litigation requirements as procedural preconditions for the arbitrators, not conditions on consent for a court to decide.

The substantive standards. Fair and equitable treatment — legitimate expectations, transparency, due process, non-arbitrariness — with the central tension being regulatory change, which is permitted absent a specific commitment. Expropriation, including indirect, subject to the police powers doctrine. National treatment and MFN, with the contested question of whether MFN reaches procedure. Full protection and security. And the umbrella clause, which elevates contract breaches into treaty breaches.

Two systems. ICSID: self-contained, no national court review, annulment only before an ad hoc committee on five narrow grounds, automatic recognition — but execution remains subject to sovereign immunity. Non-ICSID: a seat with supervisory courts, enforcement under the New York Convention.

Enforcement is the real problem. Immunity from jurisdiction and from execution are separate, and a waiver of one is not a waiver of the other. Execution reaches only property in the United States used for commercial activity, with embassy, military, and central bank assets protected, and the separate entity doctrine shielding state-owned enterprises. NML Capital permits worldwide discovery in aid of execution, which is the creditor's most useful tool.

And the advice that matters most is preventive. Structure the holding early, in a jurisdiction with a good treaty and with genuine substance. Document legality. Negotiate contractual protections including a stabilization clause and separate waivers of both immunities. And buy political risk insurance, which pays without requiring enforcement against a sovereign — because a treaty claim is a fallback, not a plan.