Throughout the 1950s and ’60s American bombers carrying nuclear weapons crisscrossed the globe, ready at a moment’s notice to fly into the heart of Russia and bomb it back to the stone age. Strategic Air Command — a now defunct branch of the U.S. Air Force — commanded this airborne alert force.

It was once the pride of the American military. For more than a decade, SAC bombers were no more than 15 minutes from nuking Russia. But the shifts on the bombers were long — sometimes more than 24 hours — and keeping such an alert force ready was taxing on pilots and crew.

There were many accidents.

In 1958, a B-47 carrying a nuke collided with an F-86 Sabre in the skies above Savannah, Georgia. The B-47 jettisoned its nuclear payload into the Atlantic Ocean. Authorities never recovered the bomb.

Months later, another B-47 dropped its nuke over South Carolina when a bomb technician aboard accidentally activated the emergency release. The bomb’s conventional explosives detonated and destroyed a nearby house.

In 1966, a B-52 crashed in Spain, spilling the nuclear guts of two bombs onto nearby farms. After the accident, Spain halted nuclear-armed American planes from passing through its air space.

Those were bad, but SAC and its airborne alert survived them. Then, in 1968, a B-52 crashed near Thule Monitoring Station in Greenland and spilled its payload all over the ice. It was one disaster too many, and it signaled the end of America’s airborne alert program … and Strategic Air Command’s prestige.

After World War II and through the ’50s, SAC worked to put more nukes on more planes. In a nuclear war, it seemed, victory would go to the aggressor. America wouldn’t throw the first nuke, but it wanted to make sure it was ready to strike back hard if Moscow dropped the bomb.

SAC soon reasoned that it could shave time off its bombing strategy if it had bombers in the air 24 hours per day, seven days a week. It may seem insane now, but it happened. In 1960, the flying branch began Operation Chrome Dome.

For the next eight years, SAC’s airborne alert bombers were always in the air and ready to drop a nuke on the Kremlin.

But there was a problem. How would America know Russia had attacked? The United States had established a perimeter of radar stations called the Ballistic Missile Early Warning System, but radar, computing and radio communication were new technologies prone to outages.

If a U.S. radar station went silent, how would the military discern whether it was because of an attack or a technical problem? This was a major concern at Thule, where the harsh Arctic climate often shut down the base’s radar and radio towers, blacking out communication.

Worse, Thule was one of America’s most important monitoring stations. If the Russians attacked, the military reasoned, they would use the polar route across Greenland to do it.

“I like to tell the commander at Thule that he will probably be one of the first ones to go if we go to war, but that there is one thing I would like to know from him and that is when he went,” Gen. Thomas Power, then head of Strategic Air Command, said at the time.

The Arctic’s climate is harsh and the radar station was fragile. Outages were frequent, and SAC needed redundancy to ensure that it didn’t attack Moscow just because it lost contact with Thule.

So SAC did what it always did. It strapped some nukes on a bomber. The air command sent one of its airborne alert bombers — complete with live nukes — to fly above the Thule monitoring station 24 hours a day … forever.

It seemed silly to keep live nukes in the air above the world’s head all day, every day. It was a sword of Damocles and it dropped in 1968.

On Jan. 21, 1968, fire swept through the cabin of the airborne B-52 watching Thule station. Smoke and flames consumed the plane and the seven crew members ejected. Six survived. The bomber crashed into an ice cap in the bay near the base.

The conventional explosives in the plane’s four hydrogen bombs exploded and cracked their nuclear payloads. Radioactive elements slid out of the bombs and onto the ice.

SAC’s Operation Chrome Dome was already on its last legs. The Thule accident just confirmed what many politicians and military leader already thought — keeping a fleet of nuclear-armed bombers in the air at all times was dangerous and insane.

In any case, politicians, the public and the military had gradually turned against the idea. The development of submarine-launched and intercontinental ballistic missiles, the need for bombers in Vietnam and preceding accidents before Thule didn’t help.

The next day, “SAC terminated the carrying of nuclear weapons aboard airborne alert aircraft,” Brig. Gen. Marshall Garth wrote in a memo. Just seven days later, SAC stopped carrying nukes on all its bombers.

This was how America balanced its nuclear triad. Bombers were and are still an important part of that strategy. But in the wake of Thule, the American military put more of its faith in ICBMs and SLBMs. A Dexedrine powered fleet of nuclear-armed bombers in the air was just too dangerous.

Only one of the B-52’s crew died during the Thule disaster, but his death wasn’t the end of the tragedy. The hydrogen bombs spread jet fuel and radioactive materials across the ice cap. It busted up the flow of the sea, blackened the ice and spread plutonium, uranium, americium and tritium into the ice and water.

Denmark — which ruled Greenland at the time — was angry. The Danes and the Americans came together quickly to clean up the mess in an effort Washington called Project Crested Ice.

The Arctic cold and winds made the project almost impossible. The temperature dipped below -70 degrees Fahrenheit, and the winds raged at more than 80 miles per hour. Despite this, the crews operated 24 hours a day until they removed the waste and recovered the bomb fragments.

It took thousands of workers and nine months to clean up Thule. They moved more than 500,000 gallons of contaminated water at a cost of almost $10 million.

The Thule disaster had long lasting effects.

In 1971, Moscow and Washington signed the “Agreement on Measures to Reduce the Risk of Nuclear War,” and agreed to inform each other when accidents such as Thule happened. Both superpowers realized they could not risk nuclear annihilation because a tragic accident looked like a nuclear attack.

Thanks to the Thule and several other SAC accidents, the U.S. military realized its nuclear bombs weren’t safe when a bomber crashed. And the Los Alamos National Laboratory developed a safer detonation method to use in America’s nuclear bombs.

But the Danish workers who helped clean up the site are dying of cancer. Crested Ice was a rush job done under pressure from the international community, and its leadership cut corners. American and Danish workers didn’t have the protective gear they needed to work with the radioactive materials.

The Danes tried to sue the United States for compensation and 1987, but failed. In 1995, Copenhagen paid a settlement to 1,700 members of the crew. Crested Ice, the plight of its workers and the possibility that America left contaminated material behind is a recurring story in the Danish press to this day.

SAC was never the same after Thule. The once prestigious society of nuclear-armed pilots dwindled as ICBMs and SLBMs grew more important. Jimmy Stewart had starred in a film based on the branch in 1955, but by the late ’80s, that fame had faded to nothing. Pres. George Bush dissolved SAC in 1992.

Then in 2007, the Air Force lost two nuclear warheads when it loaded them onto the wrong plane. The military needed a special command to handle its nukes, so it resurrected SAC and renamed it Global Strike Command.

It now controls the Air Force’s nuclear weapons.

This first appeared in WarIsBoring here.