President Ronald Reagan during a speech in Berlin in June 1987. (MIKE SARGENT/AFP/Getty Images)

One of my favorite illustrations of the little-appreciated depth of Republican foreign policy is the story of how two GOP presidents approached the Berlin Wall. In June 1982, two days after his speech predicting that "freedom and democracy" would "leave Marxism-Leninism on the ash-heap of history," President Ronald Reagan visited the wall for the first time. Gazing over the barrier that had come to symbolize the entire Cold War, then at one of its lowest points in years, he muttered, "It's as ugly as the idea behind it."

Five years later, Reagan stood at Berlin's nearby Brandenburg Gate, where he delivered another famous speech, culminating in his call for Soviet leader Mikhail Gorbachev to "tear down this wall." That speech's impact on the wall itself is easy to overestimate; internal Soviet and Eastern European dynamics likely played a much greater role. But the speech was symbolic of Reagan's forceful rethinking of American foreign policy, his conviction that he would have to attack rather than tolerate the ideological basis of the Soviet Union, and that "only killing détente could end the Cold War," as historian John Lewis Gaddis explained it.

When the Berlin Wall came down in 1989, Reagan no longer held the office that by then had transitioned to his former vice president, George H.W. Bush. Though the two were of the same party, and though Bush rode along for the Reagan foreign policy record still celebrated in GOP circles, this successor Republican president saw the wall very differently.

Reagan had exploited the Berlin Wall as a symbol of the Soviet Union's failed ideology and what he believed was its inevitable collapse, while Bush was fond of declaring that he would never "dance on the wall" to embarrass Gorbachev. His quiet support of the Soviet leader, who was slowly reforming Moscow from within and resisting hard-line generals, was a throwback to Nixon's ultra-realist foreign policy, best known for his trip to Communist China. When East Germans first breached the divider, Bush calculated that the United States had more to gain by protecting Gorbachev and the Soviet political establishment than by humiliating them, a counterintuitive and uncomfortable decision that was ultimately proven correct. 

Writer (and former Washington Post reporter and foreign editor) David Hoffman recounts Bush's reaction in his Pulitzer-winning history, The Dead Hand:

In Washington, reporters were summoned to the Oval Office at 3:34 p.m. Bush was nervously twisting a pen in his hands. He later recalled feeling awkward and uncomfortable. Ever cautious, he was worried that any comments he made could trigger a Soviet crackdown. The memory of the Tiananmen Square massacre was still fresh. Lesley Stahl of CBS News remarked that "this was sort of a great victory for our side of the big East-West battle, but you don't seem elated. I'm wondering if you're thinking of the problems."

"I am not an emotional kind of guy," Bush said.

Reagan and Bush, in their wildly different yet intrinsically Republican approaches to the same Berlin Wall, embodied a GOP foreign policy tradition that has, as many scholars have noted, seen a decline. One of those scholars is Dan Drezner of Tufts University, who has a long piece in the new issue of Foreign Affairs titled "Rebooting Republican Foreign Policy." He opens by noting that, although foreign policy has long been seen as a political advantage for Republicans, and though Mitt Romney tried to turn President Obama's foreign policy against him during the election campaign, it is one of the issues on which Obama has polled best.

The state of GOP foreign policy matters for everyone. Whether or not you happen to be a Republican yourself – or even an American – the party of Reagan, Bush, Nixon and Eisenhower still exerts a degree of power over U.S. politics, and it's probably only a matter of time until one of its members assumes the Oval Office. Rather than merely criticizing the GOP, which has been struggling to find an ideological center on foreign policy since the Iraq war divided its Nixonian realists from Reagan-style idealists, Drezner discusses how the party can rebuild its "long and distinguished foreign policy lineage."

Drezner's two big recommendations are for Republicans to rediscover non-military tools of American power (he notes George W. Bush's record of "economic statecraft" through free trade deals) and to more carefully prioritize threats and goals. Reagan, he points out, quietly withdrew from Lebanon after the 1983 attack on a U.S. Marine barracks, rather than doubling down in what could have become a costly fight with little benefit for the American interests.

But since September 11, 2001, Drezner argues, Republicans have seen more political benefit in "threat inflation" and in pushing for aggressive military action. Voters, after all, tend to punish politicians blindsided by crises and reward those who seem to tackle them proactively. "A reality check is necessary," he writes. "Precisely because Republican presidents during the Cold War took the Soviet threat seriously, they were careful not to escalate tensions needlessly."

I can't comment on the domestic politics of foreign policy, on what attracts voters or wins primaries, but the global implications of the Republican Party's foreign policy are unmissable. And it's not a one-direction phenomenon: Global opinion of the Republican Party, including among nearly every single U.S. ally, tends to be negative. That sense of feeling unwelcome may help inform the party's growing unilateralism, of imposing rather than cultivating U.S. interests abroad. One of the few foreign leaders to reach out to Republicans, Israeli Prime Minister Benjamin Netanyahu, drew sharp criticism at home for courting Romney, a move that his critics said risked Israel's close relationship with the Obama administration. As long as Republicans spurn the diplomatic world, the diplomatic world is likely to continue spurning it right back.