Both American and Soviet submarines sank during the Cold War—and because the vessels are buried deep under the ocean, the causes will probably never be known definitively.

When people think of (or remember) the Cold War, they generally recall the tensions that played out in view—American and Soviet leaders meeting at international summits, or the conflicts that the two nations fought in Vietnam and Afghanistan, or the periodic crises that threatened to plunge the world into nuclear war. Yet some of the Cold War’s most dangerous military encounters occurred silently, out of sight, hundreds of feet beneath the ocean surface.

Throughout the Cold War, American and Soviet submarines, engaged in a stealthy interplay, operated with remarkably high stakes. Carrying nuclear reactors, nuclear torpedoes, and submarine-launched ballistic missiles, these vessels operated on the margins, where a simple mechanical failure could lead to a radiological disaster or even a geopolitical flashpoint. The stakes were heightened by how unforgiving submarines are; facing external water pressure, operating with complicated nuclear propulsion systems, with the potential for fires in confined spaces. And if something did go wrong, there was little chance of rescue.

Both the US and Soviet submarine forces suffered disasters. But the Soviets, with their lower budgets and more relaxed safety culture, suffered the most. To the present day, a total of nine nuclear submarines have sunk at sea (eight submarines in total, as one astonishingly sank twice); seven of them were Soviet or Russian in origin.

Some Soviet Submarines Were “Widowmakers” in the Cold War

The most prominent disaster may be the Soviet Hotel-class submarine K-19, later dubbed the “Widowmaker.” On July 4, 1961, while operating in the North Atlantic, K-19 suffered a reactor cooling system failure. This caused the reactor temperature to rise toward a potentially catastrophic meltdown. Without a backup cooling system, the crew was forced to improvise an emergency system—and entered heavily irradiated spaces to install it.

The submarine was saved, but the sailors received enormous radiation doses. Eight sailors died within weeks, with additional deaths later associated with radiation exposure. The incident was later made into a 2002 film, directed by Kathryn Bigelow and starring Harrison Ford.

Seven years later, in 1968, the Soviet submarine K-129 disappeared in the Pacific with 98 sailors aboard. The cause remains uncertain. But what happened next is the most remarkable part: the CIA secretly located the wreck thousands of meters underwater and launched Project Azorian, an effort to secretly raise the Soviet submarine using the purpose-built Glomar Explorer. The attempt was partially successful; a section of the submarine was recovered in what is among the most audacious intelligence operations of the Cold War.

The Americans Lost Two Nuclear Submarines in the 1960s

Arguably the most significant US disaster of the Cold War involved the USS Thresher attack submarine. During deep-diving trials off Massachusetts on April 10, 1963, something went wrong, and the Thresher descended beyond crush depth and imploded. All 129 sailors aboard were killed in what still ranks as the deadliest submarine disaster in US history.

The Navy’s reconstruction of the incident focused on seawater flooding, electrical casualties, reactor shutdown, and an unsuccessful attempt to surface. The consequences led to the SUBSAFE program, which imposed rigorous standards on the systems needed for maintaining watertight integrity.

In 1968, the USS Scorpion was lost southwest of the Azores with 99 aboard. The cause was never definitively established, but probably had something to do with a torpedo casualty or an electrical failure. Whatever the cause, the fact is that both the United States and the Soviet Union lost a nuclear submarine in 1968—and neither knew exactly why.

Other subs were lost. It happened semi-regularly throughout the Cold War, demonstrating just how little control could really be exerted beneath the ocean surface. When experimental technology was combined with intelligence collection and nuclear deterrence in a hostile undersea environment, catastrophe was the inevitable outcome.

About the Author: Harrison Kass

Harrison Kass is a writer and attorney focused on national security, technology, and political culture. His work has appeared in Tablet, City Journal, The Hill, The Spectator, and The Cipher Brief. He holds a JD from the University of Oregon and a master’s in Global & Joint Program Studies from NYU. More at harrisonkass.com.

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