# International case law: war, cyber and causation

URL: https://insurancelawestonia.ee/international-insurance-case-law/war-cyber-causation-and-exclusions/
Author: Dr Olavi-Jüri Luik, Partner, Head of Insurance Law, attorney at law (Advokaadibüroo WIDEN OÜ)
Last updated: 2026-11-09

> 10 decisions of foreign courts on war, cyber and causation: summaries, paragraphs and links.

This page is part of the [overview of international insurance case law](https://insurancelawestonia.ee/international-insurance-case-law). It collects 10 decisions of foreign courts on this topic, in chronological order, with a short synthesis. Foreign decisions are not binding in Estonia. Citation conventions and links are explained on the [overview page](https://insurancelawestonia.ee/international-insurance-case-law#how-to-use-this-overview).

## Synthesis

These judgments show how courts identify the cause of loss and the reach of an exclusion where several factors contributed. English law looks for the proximate (dominant) cause and lets an exclusion operate where the excluded peril is one of equally effective causes (B Atlantic); Canada and California favour cover where an excluded and a covered cause compete (Derksen, Sabella). War and hostile act exclusions have been read in line with traditional military action rather than extended to cyber attacks (Merck), while physical damage resulting from a state attack may fall within a war exclusion even if the attacker is not identified (Nord Stream). Estonian law has no free-standing proximate cause doctrine; the insured event and exclusions follow from the contract and VÕS § 423, and exclusions are interpreted under VÕS § 39.

## Decisions

### Wilburn Boat Co. v. Fireman's Fund Insurance Co., 348 U.S. 310 (1955)

*Supreme Court of the United States, 28.02.1955* · United States, federal law · pp 316, 320-321 · marine insurance; breach of warranty; federal and state law

A boat policy contained warranties as to use and ownership, and the insurer refused payment for their breach. The US Supreme Court held that there was no established federal admiralty rule on the effect of breach of warranty (p 316), declined to fashion one (p 320) and left the matter to state law (p 321). The case explains why the strict English warranty rule cannot be assumed in US marine insurance. Relevance: the proportionate treatment of breaches of safety obligations under VÕS § 452.

[Text of the decision: govinfo.gov](https://www.govinfo.gov/content/pkg/USREPORTS-348/pdf/USREPORTS-348-310.pdf)

### Sabella v. Wisler, 59 Cal.2d 21 (1963)

*Supreme Court of California, 17.01.1963* · United States, California · California Insurance Code §§ 530, 532 · efficient proximate cause; settling exclusion; sewer line

A house subsided because a broken sewer line saturated poorly compacted fill. The policy excluded loss from settling. The Supreme Court of California held that the efficient proximate cause was the covered peril, the rupture of the sewer line, so the settling exclusion did not apply; the judgment was reversed as to the insurer. The case is the foundation of the US efficient proximate cause doctrine. Relevance: Estonian law has no equivalent doctrine; causation is addressed through contract interpretation and VÕS § 423.

[Text of the decision: law.justia.com (reprint)](https://law.justia.com/cases/california/supreme-court/2d/59/21.html)

### Derksen v. 539938 Ontario Ltd., 2001 SCC 72

*Supreme Court of Canada, 19.10.2001* · Canada · paras 6, 24-25, 30, 36-38, 46-49 · concurrent causes; automobile exclusion; CGL

A steel plate flew off an improperly secured truck load leaving a work site and struck a school bus, killing one child and seriously injuring three others (para 6). Both negligent clean-up of the site and operation of the truck caused the loss, and the CGL policy excluded loss arising from automobiles. The Supreme Court of Canada held that it is undesirable to select one 'proximate' cause among concurrent causes (para 36) and that excluding one cause does not oust cover for another unless the policy says so clearly (paras 38, 46-49); both the CGL and the motor policy responded. Relevance: overlaps between general liability and MTPL cover.

[Text of the decision: decisions.scc-csc.ca](https://decisions.scc-csc.ca/scc-csc/scc-csc/en/item/1913/index.do)

### Belt Painting Corp. v. TIG Insurance Co., 100 N.Y.2d 377 (2003)

*New York Court of Appeals, 01.07.2003* · United States, New York · total pollution exclusion; paint fumes; ambiguity

A person in an office building alleged injury from inhaling paint or solvent fumes from work by the insured painting subcontractor and sued, among others, the insured. The insurer relied on the total pollution exclusion. The New York Court of Appeals held that the exclusion was ambiguous as applied to such an ordinary workplace situation, since an average policyholder would not read it as excluding indoor paint fume injuries; summary judgment for the insured was affirmed. Relevance: the scope of pollution exclusions and the contra proferentem rule in VÕS § 39.

[Text of the decision: caselaw.findlaw.com (reprint)](https://caselaw.findlaw.com/court/ny-court-of-appeals/1084513.html)

### Flomerfelt v. Cardiello, 202 N.J. 432 (2010)

*Supreme Court of New Jersey, 07.07.2010* · United States, New Jersey · 'arising out of' exclusion; causation; duty to defend; burden of proof

A guest was harmed at a house party after taking drugs, and the homeowner's liability cover excluded injury 'arising out of' the use of controlled substances. The Supreme Court of New Jersey held that the phrase was ambiguous in context, that the exclusion requires a substantial nexus and that the insurer bears the burden of proving it. Where the facts are disputed and the loss may be covered, the insurer must defend until they are resolved. The matter was remanded.

[Text of the decision: law.justia.com (reprint)](https://law.justia.com/cases/new-jersey/supreme-court/2010/a-4-09-opn.html)

### Global Process Systems Inc v Syarikat Takaful Malaysia Berhad (The Cendor MOPU) [2011] UKSC 5

*UK Supreme Court, 01.02.2011* · United Kingdom (English law) · paras 18-19, 34, 44-46, 65, 84, 97 · marine insurance; proximate cause; inherent vice; perils of the seas

An oil rig was towed across the ocean on a barge, and its legs broke off at sea under the repeated stress of waves. Insurers relied on the inherent vice exclusion. The Supreme Court held that the proximate cause was a peril of the seas, the leg-breaking wave, not inherent vice, which denotes loss arising solely from the nature of the subject matter without any external fortuitous accident. The insurers' appeal was dismissed. Relevance: distinguishing defects of the property from external events in hull, cargo and property cover.

[Text of the decision: supremecourt.uk](https://supremecourt.uk/uploads/uksc_2010_0006_judgment_a84524617c.pdf)

### Navigators Insurance Co Ltd v Atlasnavios-Navegação Lda (The B Atlantic) [2018] UKSC 26

*UK Supreme Court, 22.05.2018* · United Kingdom (English law) · paras 22, 29-30, 39-43, 49, 55 · war risks insurance; malicious act; customs infringement exclusion; concurrent causes

A vessel was detained in Venezuela after third parties had strapped cocaine to its hull. The owner claimed under a war risks policy for a malicious act. The Supreme Court held that the smugglers had not acted maliciously, which requires an intent to cause harm or spite (paras 29-30), and that the exclusion for detention due to infringement of customs regulations applied even as a concurrent cause with an insured peril (paras 49, 55). Relevance: the operation of exclusions where causes compete.

[Text of the decision: supremecourt.uk](https://supremecourt.uk/uploads/uksc_2016_0192_judgment_d2535d9f5b.pdf)

### Merck & Co., Inc. v. ACE American Insurance Co., A-1879-21/A-1882-21 (N.J. Super. Ct. App. Div. 2023)

*Superior Court of New Jersey, Appellate Division, 01.05.2023* · United States, New Jersey · cyber attack; NotPetya; hostile or warlike action exclusion; property insurance

A pharmaceutical company's computer systems were damaged in the 2017 NotPetya malware attack, and property insurers relied on the hostile or warlike action exclusion. The Appellate Division held that the ordinary meaning and history of the exclusion tie it to the use of military force between states or military forces; it did not extend to a cyber attack on a civilian company. A leading case on the boundary between cyber risk and war exclusions. Relevance: drafting of cyber and war exclusions and the contra proferentem rule in VÕS § 39.

[Text of the decision: law.justia.com (reprint)](https://law.justia.com/cases/new-jersey/appellate-division-published/2023/a-1879-21.html)

### Great Lakes Insurance SE v. Raiders Retreat Realty Co., 601 U.S. 65 (2024)

*Supreme Court of the United States, 21.02.2024* · United States, federal law · marine insurance; choice of law; public policy

A yacht insurance contract chose New York law, and the insured sought to rely on another state's public policy. The US Supreme Court held that under federal maritime law a choice-of-law clause in a marine insurance contract is presumptively enforceable, with narrow exceptions (conflict with federal statute or policy, or no reasonable basis), and that there is no exception for state public policy. Relevance: choice-of-law clauses in cargo and hull insurance (Rome I Regulation).

[Text of the decision: supremecourt.gov](https://www.supremecourt.gov/opinions/23pdf/22-500_7k47.pdf)

### Nord Stream AG v Lloyd's Insurance Company SA and others [2026] EWHC 1685 (Comm)

*High Court, Commercial Court, 06.07.2026* · United Kingdom (English law) · paras 175, 195, 401, 404-405, 644-647 · war exclusion; explosions; property insurance; builders' risks

The Nord Stream pipelines were damaged by explosions in September 2022, and the owner claimed under its property insurance. The court held that the damage was occasioned by war and fell within war exclusion 2.i of the policy (paras 195, 647), and that it was not within the war risks cover for builders' risks either (para 175). The court made no finding as to who carried out the explosions (paras 401, 404-405) and did not decide quantum (paras 644-645). A first-instance decision; check the appeal position before citing. Relevance: wording of war exclusions and the insurer's burden of proving an exclusion.

[Text of the decision: bailii.org](https://www.bailii.org/ew/cases/EWHC/Comm/2026/1685.html)