Protecting the sea lanes of communication is actually a core US Navy mission (and probably high priorities for several other world Navies as well). Particularly

Protecting the sea lanes of communication is actually a core US Navy mission (and probably high priorities for several other world Navies as well). Particularly the major choke points: Strait of Gibraltar, Strait of Malacca, Strait of Hormuz, the Panama Canal, Suez Canal, Bab el Mandeb, Turkish Straits, and the Cape of Good Hope.