Who ended the Cold War?

MONDAY WILL mark the 20th anniversary of the fall of the Berlin Wall, an event that heralded the end of the Cold War. American conservatives give credit for the Cold War’s end to Ronald Reagan, but both Reagan and Gorbachev played big roles in ending the Cold War.

Gorbachev was the fourth Soviet leader during Reagan’s presidency. Relations between the two countries were extremely tense before he assumed power in 1985. By then, Reagan was a lame-duck president. As the 1988 presidential election approached, the Democrats’ prospects of winning were considered good. If Gorbachev wanted to continue the Cold War, he would have waited until the presidential election to see if American policy might change before capitulating to any pressure generated by Reagan’s military buildup.

Instead Gorbachev - and Reagan - pursued a different course. In Reykjavik in 1986, they nearly agreed to eliminate their countries’ nuclear arsenals. Then, in 1987, they signed the historic intermediate-range Nuclear Forces Treaty - the superpowers’ first agreement to reduce nuclear weapons.

As for Reagan’s challenge to Gorbachev to tear down the Berlin Wall, it received relatively minor media coverage at the time. Gorbachev’s role in the liberation of Eastern Europe from Soviet domination in 1989 was far more consequential. Early on, he hinted that he would no longer apply the so-called Brezhnev Doctrine, which the Soviets had used to justify military intervention in satellite countries.

Then, in a speech at the UN in December 1988, Gorbachev left no doubt. He abandoned the concept of “international class struggle’’ that had underpinned Soviet foreign policy, discarded the Brezhnev Doctrine, and renounced the use or threat of force to resolve conflicts.

Gorbachev announced unilateral measures to reduce the country’s armed forces by 500,000 troops and to withdraw 50,000 soldiers from Eastern Europe. In the words of Soviet scholar Archie Brown, he thus effectively “willed the end of communist regimes in Eastern Europe.’’

Once the dramatic changes began to unfold, Gorbachev abided by his new policy and let them run their course without interference. Restraint was not as easy politically as it now seems. As Brown has noted, the Soviet foreign-policy and military establishments had always “viewed their hegemony over Eastern Europe as non-negotiable.’’

Why did Gorbachev radically transform Soviet foreign policy? Unlike his predecessors, Gorbachev understood that the Soviet Union could never advance economically if it continued to devote 20 percent of gross national product and 40 percent of its deficit-ridden budget to military spending.

Reagan’s contribution to ending the Cold War was also important - but not in the way conservatives would have us believe. Negotiations - not military confrontation - constituted the core of his strategy for dealing with the Soviets, and he relentlessly pursued them throughout his presidency. Indeed, his military buildup was intended to create incentives for the Soviets to negotiate significant arms reductions by eliminating or reducing their advantage in various weapons categories. When Gorbachev became the first Soviet leader to engage him directly, Reagan cast aside his overheated rhetoric about “the evil empire’’ and engaged Gorbachev with respect.

Both leaders were products of a bitter, decades-long enmity stemming from the very core of their national identities, yet the two men looked beyond their expected roles in preserving the adversarial relationship between the two superpowers and their polarized ideologies and took giant steps toward peace and cooperation for the sake of their own people and the world.

They both deserve admiration for their historic achievement -and leave relevant lessons on how to confront today’s difficult challenges.

The Boston Globe // 5.11.2009