How could one city mean so much?

The Berlin Wall came down 20 years ago, but few of the news stories marking the anniversary have explained the event's full significance. The Cold War had been raging for 14 years before the wall went up on Aug. 13, 1961. How could its collapse, on Nov. 9, 1989, have heralded the Cold War's demise?

Berlin was always the centerpiece of the Cold War and, more often than many remember, very nearly the front line of real combat.

At the end of World War II, the city was divided into four sectors, each occupied by one of the four allied armies—U.S., Soviet, British, and French. As the East-West divide hardened into a Cold War, so, too, did the division of the city, into East and West Berlin.

Clearly West Berlin was an anomaly: an island of freedom locked 100 miles inside Soviet-controlled East Germany. In 1948, Josef Stalin mounted a blockade, cutting off the city from its Western suppliers. The United States responded with an airlift that went on for 300 days, until Stalin finally backed off and signed an agreement with the other three powers, guaranteeing Western access to the enclave.

Ten years later, Nikita Khrushchev resumed the pressure, announcing that within six months, he would declare the '48 agreement "null and void" and placing all of Berlin under East German sovereignty—which is to say, under Soviet control. If the West resisted, he said, there would be war.

Western intelligence agencies didn't know it at the time, but Khrushchev's threat stemmed from desperation. Over the previous decade, West Berlin had grown free and prosperous while East Berlin had stagnated under the Soviet boot. Easterners were emigrating to the West in droves, using West Berlin as their transit point. By the fall of 1958, East Germany had lost 2 million people, with continued losses of 10,000 per month, including some of its best-educated youth. Khrushchev needed to stop the hemorrhage.

When the Western leaders ignored his threat, Khrushchev knew that he would have to backpedal. The threat was a bluff; the Soviet military and economy were in dire shape; its vaunted missile program was in tatters.

So, at the start of 1959, Khrushchev sent his deputy prime minister, Anastas Mikoyan, on a goodwill trip to America, and in September, he made the voyage himself, the first time any Soviet premier had visited the United States. It was a trip of high drama and comedy from coast to coast. But the trip's purpose was fulfilled at the end, on Sept. 26 and 27, when Khrushchev and President Dwight Eisenhower met at Camp David.

At meals, the two leaders chatted amiably, mainly about their experiences in World War II. During their formal talks, they talked frankly about Berlin. (The minutes of all these meetings can be read in the State Department's historical volumes, Foreign Relations of the United States.)

Khrushchev admitted that he'd acted brashly in declaring an ultimatum on Berlin, but he said he'd been exasperated by the incessant pressure. Eisenhower acknowledged that West Berlin was an "abnormal" entity, but he emphasized that the American people would never allow anyone to grab the city unilaterally. It wasn't just a symbol of freedom. Two million people lived there; Washington was obliged to protect their security. Khrushchev asked whether he could have some assurance that the United States did not intend to occupy Berlin permanently. Eisenhower responded that he'd be very surprised if Western troops remained there for another 25 years.

At the end of the meeting, Eisenhower agreed to a summit in Paris the following year involving the four powers that had occupied Berlin since the end of the war. On the agenda would be Berlin and disarmament.

Khrushchev returned to Moscow elated. He told a Communist Party plenary session that, judging from his conversations not just with the president but with industrial leaders, most Americans did not want war and that the U.S. economy could grow without huge military spending—heresy to Leninist doctrine.

In January 1960, he gave a public speech to the Supreme Soviet, laying out an extravagant disarmament plan as a prelude to the upcoming Paris summit. The Soviets would unilaterally withdraw 1 million troops—one-third of the Soviet army—from Eastern Europe and invite NATO to respond in kind. He would also destroy all Soviet missiles and discuss on-site inspection to verify that the United States did the same.