The US, Russia, Great Britain, France, China and (recently) India have nuclear submarines.
Britain, France, Germany, Italy and USA all used submarines during WW1
From Wikipedia: Today, six countries deploy some form of nuclear-powered strategic submarines: the United States, Russia, France, the United Kingdom, People's Republic of China, and India Several other countries, including Argentina and Brazil, have ongoing projects in different phases to build nuclear-powered submarines.
The US helped France in world war 1 with submarines in the Atlantic.
During WW2 the US Navy built 126 submarines.
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52 US submarines were lost in WW2. This was about 1 in every 5 submarines that the US had in WW2
Shallow diving submarines are used for reef watching in many parts of the world.
2,200,000 Soldiers 97 Warships 40 Submarines.