The Submarine Capability of Other Nations Box B.1 lists the current submarine capabilities of nations worldwide. The United States may face a spectrum of force levels and capabilities of submarines. Many, including very capable nuclear-powered submarines operating worldwide, potentially challenging the United States in every corner of the globe. A few medium-technology submarines operating in the Persian Gulf, Strait of Hormuz, and the Arabian Sea, challenging the right of passage of ships.
All submarines are diesel unless specified.