U.S. Col. Roland Lajoie had just arrived home in West Berlin on a cool March day in 1985 when he got the call from his headquarters: the Soviets were demanding to see him immediately in East Germany

As chief of the U.S. Military Liaison Mission, Lajoie regularly sent intelligence-gathering patrols into communist East Germany and confrontations were not unusual. But he'd never gotten a call to respond personally to an incident. He remembered worrying that his men may have run over an East German civilian.

What he actually faced had even deeper political ramifications: A Soviet sentry had shot and killed unarmed U.S. Maj. Arthur Nicholson, letting him bleed out where he fell on the tank firing range he had been reconnoitering.

"Everyone knew it was kind of dangerous, but it was a big shock when Nicholson was killed," Lajoie said.

Nicholson's death 30 years ago Tuesday came only two weeks after Mikhail Gorbachev became Soviet leader. It was his first major crisis, threatening to pull Washington and Moscow back into the depths of the Cold War.

When Nicholson's body arrived back in the U.S. at Andrews Air Force Base, then-Vice President George H.W. Bush, flanked by the slain officer's wife and young daughter, slammed the Soviets, saying "this sort of brutal international behavior jeopardizes directly the improvements in relations."

Nicholson, whom everyone called "Nick," was one of 14 American officers assigned to East Germany along with support staff as part of a 1947 agreement. The Soviets were allowed to station reciprocal numbers of officers in West Germany. The Soviet and Western interpretation of where U.S., British and French teams were allowed to go differed, which led to regular run-ins and injuries, but Nicholson was one of only two mission members killed, and the only American.

"We were not cowboys, but we did tour aggressively," recalled retired U.S. Marine Col. Lawrence Kelley, who now lives in southern Germany.

The information produced by the missions, including photos of Soviet equipment and troop dispositions, was considered some of the best intelligence available since it was collected and assessed by American or other allied experts.

At times the teams would push the envelope. Nicholson himself was part of a team that got inside a Soviet tank and photographed the entire interior. But the March 24, 1985, mission was routine, and the tank firing range a target that teams had been to many times.

"It should have been a milk run," Lajoie, who retired in 1994 as a major general, said in a telephone interview from his home in New Hampshire.

Lajoie grabbed Kelley and a driver and headed out at high speed toward the site near Ludwigslust, two hours outside Berlin. Soviet troops met them and escorted them to the site — still without telling the Americans what had happened.

"It was dark by then. And there was this ring of trucks with their headlights on, illuminating the area," Lajoie said. "I thought, 'This is bad.'"

The Americans saw a vehicle with Nicholson's driver inside and asked a Soviet officer where the 37-year-old major was.

"There was a silence for about 10 seconds," Kelley recalled. "Then this colonel said 'he's dead' — that was the first time we knew."

Despite being deep inside communist East Germany and surrounded by Soviets, the two American officers decided they had nothing to lose by going on the offensive.

"We both knew as soon as we found out what had occurred that this was a big deal, and it was a lot bigger than either of us was," said Kelley, then a lieutenant colonel.

Both American officers spoke Russian. Lajoie locked horns with the Soviet commander on the scene, a three-star general who was demanding the American vehicle, Nicholson's body for an autopsy and the right to interrogate Nicholson's driver.

"This three-star launched right away into this tirade, 'We have a regrettable incident where your officer has been killed in a legal fashion by the sentry doing his job and the full responsibility lies at your feet,'" Lajoie recalled him saying.

After more than two hours, Lajoie got the general to back down. About midnight, he, his driver and Nicholson's driver took his car and the patrol vehicle back to West Berlin, leaving Kelley to watch over Nicholson's body. Kelley and the body were taken to a morgue on a Soviet base. The Soviets kept pushing again and again to perform an autopsy, but Kelley refused.

The following day, an American ambulance from West Berlin came to pick up the body, and Kelley rode with it. On the Glienicke Bridge between Potsdam and West Berlin, famously used for Cold War spy swaps, they stopped the vehicle, and Kelley replaced the blanket covering Nicholson's body with an American flag.

The Americans learned from Nicholson's driver that the officer was taking photos when the sentry, whom neither of them had spotted, fired three shots — one that whistled close to the head of the driver and one that hit Nicholson in the chest, exiting his back. There was no verbal warning, the driver said, and no warning shot as was standard Soviet protocol.

As the driver went to perform first aid on Nicholson, the sentry forced him at gunpoint back into the patrol vehicle, and there was no attempt by anyone else to provide medical assistance. A later American autopsy determined that it would have been virtually impossible to save Nicholson, even in a hospital.

"But that wasn't the point. The point was that no one knew that," Kelley said. "This lack of any humanitarian feeling was something that we slammed the Soviets for repeatedly."

But time moved on quickly, and the incident and other diplomatic issues between Moscow and Washington were put aside as the Cold War began to melt.

Over the weekend, ceremonies were held in both Ludwigslust, with American, French, British and German delegations, and in Arlington National Cemetery, where Nicholson is buried, in honor of the officer.

In 1988, Lajoie found himself heading the U.S. On-Site Inspection Agency, tasked with inspecting Soviet nuclear missiles as part of a treaty signed by Gorbachev and President Ronald Reagan.

"Three years after you have an officer killed by a sentry guarding this crappy installation with second-rate equipment, some of the same guys that I recruited to be on the INF team were going into Russia, Czechoslovakia, Germany inspecting SS20 missiles," Lajoie said. "It was an amazing flip-flop in such a short period of time."