With more than 80% of global trade by volume being transported by sea, maritime shipping lanes are indispensable to the world economy. That fact was starkly illustrated by the war in Iran, which saw Tehran effectively close the Strait of Hormuz to commercial traffic and Washington respond with a blockade of Iranian ports.
Yet such recent events are an aberration from much of the post-Cold War period, during which economic sanctions were enforced far from the sea. Governments relied on financial infrastructure – bank messaging systems, insurance markets, shipping registries and port access rules – to restrict trade without physically stopping ships.
