Marine war risk insurance fundamentally contemplates casualties caused by international conflict. But, curiously, standard clauses also exclude cover and automatically terminate war risk policies in the event of an outbreak of war between a select group of historically powerful countries: China, France, the United Kingdom, the United States, and Russia. This paper aims to demystify the origins of this five powers clause and evaluate its prospective application through the lens of an emerging breed of confrontation among the world’s major powers.