The 1945 Incident: Last Time a US Submarine Sank an Enemy Warship

In a major escalation in the ongoing conflict in West Asia, a United States Navy submarine reportedly intercepted and sank an Iranian warship in the Indian Ocean on March 3.

The strike is said to have resulted in significant casualties and marks a rare instance of modern undersea combat. Pete Hegseth confirmed that the vessel was destroyed by a torpedo launched from a US submarine. The incident is being described as the first time since World War II that an American submarine has sunk an enemy warship using torpedoes in combat.

A rare return to torpedo warfare

Before this incident, the last recorded submarine-launched torpedo kills by the United States occurred in the closing hours of World War II in August 1945.

One such engagement involved USS Spikefish (SS-404), which attacked the Japanese transport submarine Japanese submarine I-373 in the East China Sea on August 14, 1945. Firing six torpedoes from about one kilometre away, the Spikefish scored two direct hits, sinking the vessel within minutes and causing heavy casualties.

Later that day, USS Torsk (SS-423) carried out another attack near Maizuru. The submarine first sank the Japanese escort ship CD-47 using a Mk-28 torpedo. Shortly afterward, it fired an acoustic-homing Mk-27 “Cutie” torpedo that destroyed CD-13.

Military historians widely regard the sinking of CD-13 by USS Torsk as the final Japanese warship lost during World War II.

Changing role of submarines

The contrast between the Pacific battles of 1945 and the recent strike highlights the long gap in direct submarine combat. For decades, US submarines have largely focused on strategic deterrence, surveillance and intelligence gathering rather than ship-to-ship engagements.

Despite remaining a core element of American naval power, submarine operations in the modern era have rarely involved torpedo attacks on enemy warships. The reported sinking of the Iranian vessel therefore represents an unusual operational deployment of heavyweight torpedoes in active combat and signals a tougher US military posture in the region.