K-129 was a Project 629A (Russian: проект 629А, proyekt 629A; NATO reporting name Golf II–class) diesel-electric-powered ballistic-missile submarine that served in the Pacific Fleet of the Soviet Navy.

The K-129's commander was Captain First Rank Vladimir I. Kobzar, and she carried the hull number 722 on her final deployment, during which she sank on 8 March 1968 along with her missiles and their nuclear warheads.

After nearly two weeks of silence during her patrol in the Pacific Ocean, the Soviet Navy officials became concerned about her status and reportedly deployed large numbers of military aircraft and ships to search for the vessel, but no sign or wreckage was found.

In January 1968, K-129 was assigned to the 15th Submarine Squadron as part of the 29th Ballistic Missile Division at Rybachiy, commanded by Admiral Viktor A. Dygalo.

Upon departure on 24 February, K-129 reached deep water, conducted a test dive, returned to the surface and reported by radio that all was well, and proceeded on patrol.

Soviet naval headquarters declared K-129 missing by the third week of March, and organized an air, surface, and underwater search-and-rescue effort in the North Pacific from Kamchatka and Vladivostok.

U.S. SOSUS naval facilities in the North Pacific were alerted and requested to review acoustic records on 8 March 1968 to identify any possible anomalous signal.

The International Atomic Energy Agency states that two nuclear warheads from K-129 were located in the Pacific 1,230 miles from Kamchatka at coordinates 40°6'N and 179°57'E at a depth of 6,000 metres (20,000 ft), and lists them as recovered.

[12] Seymour Hersh of The New York Times uncovered some of the details of Project Azorian in 1974, but was kept from publication by the action of the Director of Central Intelligence, William Colby.

The CIA argued in a Freedom of Information Act lawsuit, however, that the project had to be kept secret because any "official acknowledgment of involvement by U.S. government agencies would disclose the nature and purpose of the program.

John Craven, former chief scientist of the U.S. Navy's Special Projects Office and former head of the DSSP and DSRV programs, commented: I have never seen or heard of a submarine disaster that was not accompanied by the notion that the battery blew up and started it all.

One accused the Americans of acting like a "criminal that had been caught and now claimed that guilt must be proved," according to the notes of a U.S. participant in a November 1999 meeting on the topic.

In the case of the Project 667A, the missiles were located within the pressure hull, and the explosion did not cause damage sufficient to immediately sink the boat.

It did, however, cause extensive radioactive contamination throughout, requiring the submarine to surface and the evacuation of the crew to the weather deck, and later to a rescue vessel, which had responded to the emergency.

First, the radioactive contamination by weapons-grade plutonium of both the recovered bow section and the six crewmen of K-129 indicates the explosion of the warhead detonator charge of one of the missiles, before the ship reached its crush depth.

Since K-129's missiles were housed in the sail, much less structural mass (compared to the K-219) was available to contain such an explosion, and loss of depth control of the submarine would be instantaneous.

According to Craven, K-129 crossed the International Date Line at 40°N, which was much further south of her expected patrol station: When K-129 passed longitude 180, it should have been further north, at a latitude of 45°, or more than 300 miles away.

According to an internal intelligence memo directed to Henry A. Kissinger in May 1974, K-129's recovery site is within the 500 nm transit lane used by a Soviet Yankee-class submarine on its initial deployment to the East Pacific.

[24] Vladimir Evdasin (Владимир Евдасин), who from June 1960 to March 1961 served aboard K-129, reported that K-129 was sent on a secret mission in response to the substantial U.S. naval force build-up off the Korean coast after the Pueblo incident.

The premise of Red Star Rogue is that a fail-safe device designed to be activated in the event of an unauthorized fire command of its nuclear missiles caused two catastrophic explosions (monitored by U.S. technology at the time) had sunk the submarine.

[28] Red Star Rogue claims the changing relations with China and Russia in the early 1970s, forged by Nixon and Kissinger, were enabled by the K-129 incident.

Such information could be (and supposedly was) used within Henry Kissinger's foreign policy of "Deterrence Through Uncertainty", to "raise an unanswerable question in Leonid Brezhnev's mind about his command and control of his armed forces".

"[20] In 1995, when Huchthausen began work on a book about the Soviet submarine fleet, he interviewed Russian Navy Rear Admiral Viktor Dygalo, who claimed that the true history of K-129 has not been revealed because of the informal agreement between the two countries' senior naval commands.

In October 1992, Robert Gates, as the Director of Central Intelligence, visited Moscow to meet with President Boris Yeltsin of Russia.

[29]Gates's decision to bring the videotape of the funeral held for the men on the Golf was ultimately motivated by the fact that the United States wanted to inspire Russia to offer up information on missing American servicemen in Vietnam.

But then when we started asking the Russians about what had happened to U.S. pilots shot down over Vietnam, and if any U.S. POWs had been transferred to Russia and held there, they came back and said, "What about our guys in the submarine?"

Swordfish was the U.S. submarine involved – a charge based solely on the latter's reported arrival in the Ship Repair Facility, Yokosuka, Japan, on 17 March 1968, with a badly damaged sail.

The joint commission, headed by General Volkogonov and Ambassador Toon, informed the Russians that no U.S. submarines on 8 March 1968, had been within 300 nautical miles (560 km) of the site where the K-129 was found.