The United States sells everything, why doesn’t it sell submarines? Even if it doesn’t sell nuclear submarines, it doesn’t sell conventional ones either.

Because the United States does not have conventional combat submarines.

The "Dolphin" submarine was commissioned in the late 1960s. It is one of the oldest submarines and the only diesel-electric submarine currently in service in the U.S. Navy and is used for scientific research.

The United States has sold conventional submarines to Taiwan, but they were built during World War II and are still in service in Taiwan.

At present, no country has sold nuclear submarines, which are classified as core secrets.