The U.S. Navy has reached a Cold War-era milestone in the Arctic, deploying two Virginia-class submarines beneath the polar ice cap for the 100th time since World War II.

Japan now operates five cutting-edge Taigei-class submarines, in addition to its 12 Soryu-class and 6 Oyashio-class vessels.

The Pentagon has not said which American submarine fired the torpedo, except to say it was a fast-attack submarine.

The Iranian warship that was sunk in the Indian Ocean likely didn’t have the technology needed to defend itself against submarines.

China has ramped up its production of nuclear-powered submarines over the past five years to the point where it is launching subs faster than the United States, threatening to negate a sea-power ...

Here’s what you’ll learn when you read this story: For the first time, China has outstripped U.S. nuclear-powered submarine production. U.S. plans to shore up an aging submarine fleet are delayed.