Sinking a ship in international waters an undeclared war is clearly a war crime.
War cannot be insured. War crimes are definitely uninsurable.
AI Overview
Standard insurance policies almost universally contain "war exclusion" clauses, meaning damage, liability, or losses directly caused by war, declared or undeclared, acts of foreign enemies, or hostilities are not covered. These risks are considered uninsurable due to their catastrophic, unpredictable, and widespread nature, which could bankrupt insurers.
Even Stevie Wonder saw this coming.