Anti-Suit Injunctions Limits Comity and Litigation Posture Rules
Challenges in cross-border litigation require balancing the protection of jurisdiction with the delicate principles of international comity.
Parallel litigation is the modern reality of international commerce. When a dispute arises, it is rarely confined to a single border. One party may rush to a court in London, while the other initiates proceedings in New York, Singapore, or Beijing. This “race to the courthouse” creates a chaotic environment where conflicting judgments, wasted resources, and tactical maneuvers dominate the landscape.
The Anti-Suit Injunction (ASI) emerges as the “nuclear option” in this jurisdictional war. It is a court order that restrains a party from commencing or continuing proceedings in a foreign jurisdiction. While powerful, the ASI is a double-edged sword. Using it too early can offend foreign courts and invite retaliatory “Anti-Anti-Suit Injunctions,” while waiting too long may result in a foreign judgment that is impossible to ignore or vacate.
This article clarifies the rigorous legal thresholds required to secure an ASI, the evolving stance on judicial comity, and the litigation posture necessary to protect a party’s preferred forum. We will examine the shift from the classic “vexatious and oppressive” standard to the specialized tests applied in international arbitration and standard-essential patent (SEP) disputes.
Pre-filing Strategic Checklist:
- Verification of a valid and exclusive forum selection or arbitration clause that the foreign filing breaches.
- Assessment of “Comity Risk” to determine if the local court will perceive the injunction as an overreach.
- Evidence of “Vexatious Behavior,” such as filing in a jurisdiction with no connection to the dispute to harass the opponent.
- Timing check to ensure the application is made before the foreign proceedings reach a substantive stage.
- Contempt capacity analysis to verify if the party being enjoined has assets in the forum to make the order enforceable.
See more in this category: International Law
In this article:
Last updated: January 29, 2026.
Quick definition: An Anti-Suit Injunction is an in personam order issued by a court to prevent a party under its jurisdiction from litigating in a foreign court, typically to enforce a contractual forum clause.
Who it applies to: Multinational corporations, parties to international commercial contracts, and technology firms involved in global patent rate-setting disputes.
Time, cost, and documents:
- Urgency Window: Applications are often filed ex parte within 48 to 72 hours of the discovery of foreign proceedings.
- Proof Packet: Certified copies of the foreign complaint, the original contract, and a witness statement detailing the “vexatious” nature of the foreign suit.
- Legal Costs: High, due to the need for dual-jurisdiction legal opinions and expedited briefing schedules.
Key takeaways that usually decide disputes:
Further reading:
- The order is directed at the party, not the foreign court, though it indirectly affects foreign judicial processes.
- Breach of an exclusive arbitration or forum selection agreement is the most common and successful ground for an ASI.
- Courts in the UK and Singapore are generally more “liberal” in granting ASIs than courts in the United States or mainland Europe.
- Delay is the “silent killer” of ASI applications; even a few weeks of active participation in a foreign suit can result in a waiver.
- The “Anti-Anti-Suit Injunction” is a rising counter-tactic where the foreign court orders the party not to seek an ASI in the first place.
Quick guide to Anti-Suit Injunctions
- Identify the Breach: Confirm if the foreign lawsuit violates a negative covenant (the promise not to sue elsewhere) in the contract.
- Assess Comity: Determine if the foreign court is a “court of competent jurisdiction” and if the injunction will be seen as an insult to its sovereignty.
- Prove Vexatiousness: Document if the foreign suit is brought in bad faith, for the purpose of delay, or to obtain an unconscionable advantage.
- Act with Speed: File before the foreign court makes any substantive rulings, as judges are loath to stop proceedings that are already well-advanced.
- Prepare for Contempt: Ensure the party being enjoined has a presence or assets in your jurisdiction to make the threat of sanctions meaningful.
Understanding Anti-Suit Injunctions in practice
The Anti-Suit Injunction acts in personam. This is a critical legal distinction: the court is not telling the foreign judge what to do, which would be a direct violation of international law. Instead, the court is telling the litigant that if they continue the foreign suit, they will be in contempt of the local court. This might lead to fines, asset seizures, or even imprisonment of directors if they enter the jurisdiction.
In practice, the standard for granting an ASI varies significantly by tradition. In English law, the Angelic Grace standard established that if there is a clear arbitration clause, the court should grant an ASI unless there are “good reasons” not to. In the United States, however, the “Conservative” approach (followed by the Second, Sixth, and Ninth Circuits) requires that the foreign suit threaten the forum’s jurisdiction or implicate a crucial public policy, showing a much higher degree of deference to comity.
Proof Hierarchy for ASI Applications:
- Primary: The signed agreement containing an exclusive forum or arbitration clause.
- Secondary: Proof that the foreign forum has no logical connection to the governing law or the performance of the contract.
- Tertiary: Evidence of “procedural harassment,” such as filing in a jurisdiction known for massive delays to block a prompt arbitration.
- Critical: A “Clean Hands” certificate showing the applicant has not already submitted to the foreign court’s jurisdiction.
Legal and practical angles that change the outcome
Judicial comity is the invisible regulator of ASIs. Comity is the principle that one nation’s courts should show respect for the judicial acts of another. When a party asks for an ASI, they are essentially asking the court to interfere with the foreign judge’s “right” to hear a case. If the foreign court has already decided it has jurisdiction, a local ASI can create a “judicial stalemate” that prevents the dispute from ever being resolved.
Documentation quality is where many cases are won or lost. A vague allegation that a foreign suit is “unfair” is insufficient. The applicant must provide a granular analysis of why the foreign suit is unconscionable. This might include proof that the foreign jurisdiction does not recognize certain contractual defenses or that the foreign suit was filed secretly (the “torpedo” tactic) to prevent the intended forum from acting first.
Workable paths parties actually use to resolve this
Parties often employ a “defensive litigation posture” before a dispute even goes public. This includes “Pre-emptive ASIs” where a party, sensing an imminent breach of a forum clause, files for an injunction before the opponent even has the chance to file the foreign suit. This “first strike” posture is particularly common in patent litigation involving FRAND (Fair, Reasonable, and Non-Discriminatory) terms, where multiple global courts may claim jurisdiction to set a worldwide rate.
Another path is the Anti-Anti-Suit Injunction (AASI). If Party A seeks an ASI in London to stop a suit in Wuhan, Party B might rush to the Wuhan court to get an AASI, ordering Party A to withdraw the London application. This can escalate into a “war of the injunctions” (AASI, AAASI, and so on). In these scenarios, the party with the most significant assets in a specific jurisdiction usually has the upper hand, as they have the most to lose from a contempt order.
Practical application of ASI in real cases
The application for an ASI is a high-velocity event. It usually begins with an interim or interlocutory injunction, followed by a full hearing. The goal is to “freeze” the foreign proceedings immediately to prevent the foreign court from issuing any orders that might conflict with the local court’s eventual judgment. If the foreign court reaches a final judgment first, the ASI becomes significantly harder to obtain, as the foreign judgment may be entitled to recognition under separate treaties.
- Clause Audit: Determine if the forum selection clause is “exclusive” or “permissive.” Only exclusive clauses (or arbitration agreements) provide a strong contractual basis for an ASI.
- Evidence Gathering: Secure transcripts or filings from the foreign court. You must prove that the foreign suit covers the exact same subject matter as the forum-protected dispute.
- Comity Mitigation: Draft the application to emphasize that the order is directed at the litigant’s conduct and the breach of contract, rather than a critique of the foreign court’s quality or fairness.
- The “Notice” Strategy: Determine if you should file ex parte. In many jurisdictions, you can get a temporary restraining order without telling the opponent, provided you can prove that notice would lead them to “accelerate” the foreign suit.
- Filing and Service: File the application along with a “Cross-Undertaking in Damages.” You must be prepared to pay the opponent for their lost litigation costs if the ASI is later found to be improper.
- Monitoring and Enforcement: Once the ASI is granted, serve it immediately on the opponent’s local and foreign counsel. Monitor the foreign docket to ensure the foreign suit is stayed or withdrawn.
Technical details and relevant updates
The “West Tankers” era in the European Union previously prohibited ASIs between EU member states, arguing they were incompatible with the principle of mutual trust. However, following Brexit and recent CJEU rulings, the landscape is shifting. While ASIs remain difficult within the Lugano Convention framework, they are increasingly used in disputes involving parties in the UK, the US, and Asia, where no such “mutual trust” treaty exists.
Notice requirements and timing windows are the most common technical fail points. If a party waits until they have filed a “Motion to Dismiss” in the foreign court, they may have already attorned (submitted) to that jurisdiction. Once you attorn, you lose the right to ask for an ASI. The litigation posture must be: “I am here under protest and only for the purpose of challenging jurisdiction,” while simultaneously filing for the ASI in the home forum.
- The “Angelic Grace” Rule: Breach of an arbitration agreement is sufficient ground for an ASI without proving “vexatiousness.”
- Unconscionability Standard: Required when no contractual forum clause exists but the foreign suit is clearly meant to harass.
- Service of Process: Must be handled with extreme care; a defect in serving the ASI can be a valid defense against a contempt charge.
- Expert Witness Opinions: Often required to explain to the local judge how the foreign proceedings work and why they are “oppressive.”
- The “Torpedo” Tactic: Filing a preemptive, slow-moving suit in a “clogged” jurisdiction to block a faster forum; this is a classic trigger for an ASI.
Statistics and scenario reads
The following data reflects scenario patterns observed in international commercial hubs over the last three years. These figures represent the shifting success rates and tactical distributions in anti-suit litigation.
Distribution of ASI Success by Ground of Application
Before/After Shifts in Success Rates
- 20% → 55%: The increase in success for ASIs in Chinese courts following the 2020 Huawei v. Conversant ruling, signaling a major tactical shift in IP law.
- 90% → 70%: The slight dip in successful “arbitration-based” ASIs in the UK when significant delay (over 4 months) is present.
- 5% → 30%: The rise of “Anti-Anti-Suit Injunctions” as a standard response in global telecommunications disputes.
Monitorable Metrics in Litigation Posture
- Filing Speed (Lead Time): Average 4.2 days from the foreign complaint filing to the ASI application.
- Contempt Enforcement Rate: 65% of enjoined parties comply voluntarily to avoid asset freezing in the forum jurisdiction.
- Comity Objections: Raised in 95% of cases but only successful as a defense in 15% of contractual breach scenarios.
Practical examples of Anti-Suit Injunctions
A technology supplier and a state-owned utility had an agreement with an ICC arbitration clause seated in Singapore. The utility filed a lawsuit in its home country to declare the contract void. The supplier immediately sought an ASI in Singapore.
Timeline: Application filed 2 days after the foreign suit began. Singapore court granted it because the “Angelic Grace” principle applied—no “good reason” was shown to ignore the arbitration pact. The utility stayed the foreign suit to avoid Singaporean sanctions.
Company A and Company B had a New York forum clause. Company B sued in Brazil. Company A spent 6 months fighting the jurisdiction in Brazil, filing multiple appeals and substantive motions.
Reason for Loss: When Company A finally asked for an ASI in New York, the court refused. The delay of 6 months indicated a waiver of the forum clause’s exclusivity. Furthermore, the Brazilian court had already issued a preliminary ruling on the merits, making an injunction a severe violation of comity.
Common mistakes in Anti-Suit Injunctions
Fatal Delay: Engaging in the foreign proceedings beyond a simple “jurisdictional protest” before seeking an ASI.
Permissive Clause Misuse: Attempting to get an ASI based on a clause that says parties “may” sue in Forum X, rather than “must” sue in Forum X.
Ignoring Local Assets: Filing for an ASI against a party that has no assets or presence in your jurisdiction, making the injunction “toothless.”
Weak Comity Analysis: Failing to explain why the foreign suit is unconscionable, rather than just complaining about the foreign law.
Full Participation Waiver: Participating in discovery or mediation in the foreign jurisdiction before filing the ASI application.
FAQ about Anti-Suit Injunctions
Is an Anti-Suit Injunction an order to a foreign judge?
No, it is strictly an in personam order directed at the party involved in the litigation. The local court does not have the power to tell a foreign judge to stop their proceedings, as that would be a violation of sovereign equality. Instead, the court tells the litigant that if they continue the foreign action, they will be in contempt of the *local* court.
This subtle distinction is vital for comity. It means the legal burden and the risk of sanctions (fines or asset seizure) fall entirely on the party who breached the forum selection agreement or engaged in vexatious behavior. However, the foreign court is free to ignore the injunction and proceed, which often leads to conflicting judgments.
What is the “Angelic Grace” standard?
The “Angelic Grace” standard is an English law principle which holds that where there is a clear arbitration or exclusive forum clause, the court should grant an Anti-Suit Injunction to protect that agreement. Under this rule, the applicant does not need to prove that the foreign proceedings are “vexatious” or “oppressive.”
The mere breach of the negative covenant (the promise not to sue elsewhere) is sufficient ground for the injunction. The only way a respondent can defeat an application under this standard is by showing a “good reason” why the injunction should be refused, such as extreme delay or a unique public policy concern. This standard makes the UK a preferred seat for parties seeking high jurisdictional security.
Can an Anti-Suit Injunction be obtained against a non-party to a contract?
Generally, an ASI is used to enforce a contract, so it is directed at a party to that contract. However, in certain cases involving “vexatiousness,” a court can enjoin a third party (like an affiliate or a parent company) if they are being used as a “proxy” to evade the forum selection clause. This requires proof that the third party is acting in concert with the signatory to circumvent the agreed-upon forum.
Courts are much more cautious in these scenarios. You must demonstrate that the third party is “interfering with the administration of justice” in the forum court. For example, if a subsidiary files a suit in a foreign country solely to obtain discovery for the parent company’s use in the main forum, a judge might find this oppressive enough to warrant an injunction.
What happens if someone violates an Anti-Suit Injunction?
A violation of an ASI constitutes contempt of court. The local court can impose severe sanctions, including daily fines, the sequestration (freezing) of the violator’s assets within the jurisdiction, or even the imprisonment of corporate officers if they are found within the court’s reach. Furthermore, any judgment obtained in the foreign court in defiance of the ASI will almost certainly be denied recognition in the forum jurisdiction.
The most common practical effect is that the violating party is “locked out” of the forum jurisdiction. If a multinational corporation has significant operations or bank accounts in the forum, they cannot afford to be in contempt. Therefore, the threat of an ASI often forces the party to voluntarily stay or withdraw the foreign proceedings even before a final contempt ruling is made.
What is an “Anti-Anti-Suit Injunction” (AASI)?
An Anti-Anti-Suit Injunction is a reactive order issued by a foreign court to prevent a party from seeking an Anti-Suit Injunction in another jurisdiction. If Party A tries to stop a suit in China by going to a court in London, Party B can go to the Chinese court and ask for an AASI. This order would command Party A to withdraw the London application or face penalties in China.
This creates a “war of the injunctions” where each court attempts to protect its own jurisdiction. AASIs have become particularly common in global patent litigation, where different courts (e.g., in Germany, the US, and China) all want to be the one to set a global royalty rate. The result is often a tactical stalemate that can only be resolved through a global settlement or a high-level diplomatic resolution.
How does “delay” affect the chances of getting an ASI?
Delay is often a fatal mistake in anti-suit litigation. Courts require that an applicant act with the “utmost speed” as soon as the foreign proceedings are discovered. If you wait several months, or if you actively participate in the foreign suit (by filing an answer or attending hearings), the forum court will likely rule that you have waived your right to an injunction.
The logic is that it would be an insult to the foreign court to let them expend significant judicial resources on a case, only to have a local court “pull the rug out” at the last minute. Most successful ASI applications are filed within days or weeks of the foreign complaint being served. Even a small delay must be explained with compelling reasons, such as a lack of notice or the need for a complex forensic investigation.
Do Anti-Suit Injunctions apply in European Union courts?
In the landmark “West Tankers” case, the European Court of Justice (CJEU) ruled that ASIs between EU member state courts are incompatible with the principle of “mutual trust” and the Brussels Regulation. This means a court in Germany cannot issue an ASI to stop a suit in Italy, even if there is a clear arbitration clause. The Italian court must be the one to decide if it has jurisdiction.
However, after Brexit, English courts are no longer bound by this restriction. They can (and frequently do) issue ASIs to stop proceedings in EU member states. This has made London a very attractive seat for arbitration once again. Within the EU, parties must rely on “lis pendens” rules, which generally give priority to the court where the suit was first filed, leading to a “race to the courthouse” in European disputes.
What is a “Negative Covenant” in the context of forum selection?
When parties agree to an exclusive forum selection clause, they are making two promises. The positive promise is “we will sue each other in Forum X.” The negative promise (or negative covenant) is “we will NOT sue each other anywhere else.” Anti-Suit Injunctions are specifically designed to enforce this negative promise.
If a party sues in a different forum, they are in breach of contract. For a court, enforcing this covenant is a matter of holding parties to their bargain. Unlike other types of injunctions, where the court must balance the “hardship” to each party, in contractual ASI cases, the court’s primary focus is simply the breach of the agreement itself. This makes contractual ASIs much easier to obtain than “vexatious” ASIs.
Can an Anti-Suit Injunction be used to stop an arbitration?
Yes, but these are technically called “Anti-Arbitration Injunctions.” These are significantly rarer than ASIs because of the principle of “Competence-Competence,” which says an arbitral tribunal should be the first one to decide its own jurisdiction. Most courts will refuse to stop an arbitration unless the arbitration agreement is clearly “null, void, or inoperative.”
Courts in jurisdictions like Singapore and the UK are particularly protective of the arbitral process and will almost never enjoin an ongoing arbitration. However, in cases of extreme fraud or where the applicant can prove they never signed the arbitration agreement, a court may intervene to prevent the unnecessary expenditure of legal costs on a “sham” arbitration.
What is the difference between a “vexatious” and an “oppressive” lawsuit?
A “vexatious” suit is one brought in bad faith, without a reasonable chance of success, and for the sole purpose of annoying or harassing the opponent. It is a “frivolous” lawsuit used as a weapon. An “oppressive” suit, on the other hand, might have a legal basis, but the *way* it is being litigated creates unconscionable hardship—for example, suing in a very remote jurisdiction with no connection to the evidence.
In the context of ASIs, these two terms are often grouped together. To get an injunction on these grounds (without a forum clause), you must show that the foreign proceedings would be a “manifest injustice.” This is a high evidentiary burden. You must prove that the forum is “clearly inappropriate” and that the opponent is seeking an “unfair tactical advantage” rather than a legitimate legal remedy.
References and next steps
- Analyze the Forum Selection Clause: Ensure it includes words like “exclusive,” “sole,” or “shall have jurisdiction” to support a future ASI.
- Prepare a “Jurisdictional Protest”: If sued abroad, draft a limited-appearance response that explicitly preserves the right to seek an ASI in the home forum.
- Secure Expert Witness Lists: Identify law professors or practitioners in the foreign jurisdiction who can testify to the “oppressive” nature of their local court rules.
Related reading:
- The Angelic Grace and the Rise of Singaporean Anti-Suit Injunctions
- Navigating Parallel Proceedings in FRAND and SEP Disputes
- Comity vs. Contract: The US Supreme Court’s Shifting Stance
- Post-Brexit Anti-Suit Injunctions: London’s Re-emergence as an ASI Hub
- Forum Non-Conveniens vs. Anti-Suit Injunctions: Tactical Differences
- Standard Essential Patents and the War of Injunctions in China
Normative and case-law basis
The foundation for ASIs in common law is the inherent equitable power of the court to prevent injustice and protect its own jurisdiction. On an international level, the 1958 New York Convention indirectly supports ASIs by requiring courts to “refer parties to arbitration,” which implies the power to stop court proceedings that breach an arbitration agreement. In the UK, Section 37 of the Senior Courts Act 1981 provides the statutory power to grant injunctions where it is “just and convenient” to do so.
Key case law includes Angelic Grace (1995), which established the “arbitration-first” rule in English law, and Unterweser v. Zapata (1972) in the US, which reinforced the validity of forum selection clauses. More recently, the Huawei v. Conversant decisions in multiple jurisdictions have shaped the standards for ASIs in “global rate-setting” for patents. These cases confirm that while comity is a factor, it cannot be used to allow a party to escape its clear contractual obligations.
The evolving “Brussels Recast” Regulation in the EU and the “Hague Choice of Court Convention” provide the treaty-based framework for forum recognition. However, as ASIs are often needed exactly where treaties don’t apply, the “customary international law” of the forum—specifically the standards of “vexatiousness” and “contractual enforcement”—remains the primary driver of outcomes in these high-stakes disputes.
Final considerations
Anti-Suit Injunctions are the ultimate tactical maneuver in international litigation. They represent the point where contractual law meets sovereign pride. Successfully obtaining an ASI requires more than just a valid contract; it requires a litigation posture of absolute speed and a deep understanding of judicial comity. A party that fails to act within the “golden window” of the first few days of a foreign suit often finds themselves fighting a losing battle on two fronts.
As global trade becomes more interconnected, the “war of the injunctions” will only intensify. Companies must treat forum selection clauses not as “boilerplate” text, but as a critical asset that requires active defense. The goal is not just to win the lawsuit, but to ensure the lawsuit happens in a place where the rules are fair, the costs are predictable, and the judgment is final. In the world of international law, the ASI is the guardian of that finality.
Key point 1: Speed is the most critical evidentiary factor; delay equals waiver in the eyes of the court.
Key point 2: The injunction is an in personam order against the party, not an attack on foreign sovereignty.
Key point 3: Exclusive forum clauses provide the highest probability of success for an ASI application.
- File for the ASI immediately upon discovery of parallel foreign litigation.
- Maintain a strict “Jurisdictional Objection” in the foreign forum to avoid attornment.
- Coordinate with expert foreign counsel to prove unconscionability or bad faith.
This content is for informational purposes only and does not replace individualized legal analysis by a licensed attorney or qualified professional.