The United States, with its blue-water navy, is commonly viewed as a Thalassocracy by a certain segment of the historian community. You can really go down the rabbithole but basically some people view the US as, at least in part, having the culture of an island scaled up to the size of a continent.

There's a similar train of thought that sea-based empires defeat land-based empires when the two do battle and some people view the conflict between the USSR and the United States during the cold war through that lense.