A submarine might lack the visual drama of a fighter jet or the sheer size of an aircraft carrier, but beneath the waves, it's among the most powerful tools in modern warfare. Often called “the silent service” for their ability to vanish from radar, these stealth vessels can control strategic sea routes, track enemy fleets, and even carry nuclear missiles capable of striking across continents.
Because fleets are closely guarded state secrets, the exact numbers are hard to pin down, but reliable estimates show which nations are leading the underwater arms race. From global superpowers to rising naval challengers, here’s a look at the countries commanding the largest submarine fleets beneath the surface. Click on.