U.S. Navy Sinks Iranian Warship with Torpedo Attack

The strike by a U.S. submarine using a Mark 48 torpedo sends a strong strategic message to Iran and China.

Mar. 19, 2026 at 1:55am

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In a rare modern naval combat operation, a U.S. Navy submarine sank an Iranian warship, the IRIS Dena, off the coast of Sri Lanka using a Mark 48 torpedo. The strike, conducted by the USS Charlotte, a nuclear-powered fast attack submarine, demonstrates the continued strategic importance of conventional weapons like torpedoes even as warfare becomes increasingly dominated by unmanned systems.

Why it matters

The use of a submarine-launched torpedo, a stealthy and devastating weapon, to sink the Iranian ship sends a clear message of U.S. military capability and resolve to both Iran and China. Submarines are considered apex predators in naval warfare, and the U.S. decision to unmask this capability signals it is willing to aggressively defend its interests.

The details

The Mark 48 MOD 7 torpedo used in the strike is a wire-guided, acoustic-homing weapon with a 650-pound warhead. Rather than striking the ship directly, the torpedo creates a powerful air bubble that rises up and breaks the ship's keel, causing it to quickly sink. This unconventional method of sinking ships through water pressure is a key capability of the Mark 48.

  • On March 4, 2026, a U.S. Navy submarine sank the Iranian warship IRIS Dena off the coast of Sri Lanka.

The players

USS Charlotte

A nuclear-powered fast attack submarine of the U.S. Navy that conducted the torpedo strike against the Iranian warship.

IRIS Dena

An Iranian warship that was sunk by a U.S. Navy submarine using a Mark 48 torpedo.

Dr. Steven Wills

A navalist for the Center for Maritime Strategy at the Navy League of the United States who provided expert analysis on the strategic significance of the torpedo strike.

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What they’re saying

“When countries unmask their submarine force, that's significant. A submarine is as much of – and in some cases more of – a capital warship than an aircraft carrier is. It's an honest-to-goodness apex predator killer. Countries don't unleash these unless they mean business.”

— Dr. Steven Wills, Navalist, Center for Maritime Strategy at the Navy League of the United States

“It doesn't hit the ship. It runs underneath the ship and explodes, and creates this air bubble that rises up and breaks the keel of your target, fatally damaging it. It's like breaking a person's backbone. When the bubble collapses, the ship drops back down. Basically, it breaks in half and sinks very quickly.”

— Dr. Steven Wills, Navalist, Center for Maritime Strategy at the Navy League of the United States

“When you send a nuclear submarine, it's like sending James Bond to go eliminate somebody, no matter what the target is. I think it means the United States unmasked its killer weapon.”

— Dr. Steven Wills, Navalist, Center for Maritime Strategy at the Navy League of the United States

What’s next

The U.S. Navy is expected to continue monitoring the situation in the region and may take additional actions if tensions with Iran escalate further.

The takeaway

This torpedo strike demonstrates that even as warfare becomes increasingly dominated by unmanned systems, conventional weapons like submarines and torpedoes remain a critical part of the U.S. military's strategic arsenal. The use of this stealthy and devastating capability sends a clear message to adversaries about American resolve and willingness to defend its interests.