Which version of the Gipper would Republicans like Obama to emulate?

Mann writes that these comments—which were seen as an answer to Dobrynin's plea—strengthened Gorbachev's hand at the Communist Party congress a few weeks later, allowing him to argue that his next round of reforms could be passed, and further steps toward disarmament taken, without any danger.

In his first term, from 1981-85, Reagan escalated East-West tensions, spoke in bellicose rhetoric, and jacked up military spending to 30-year highs. This is the Reagan whom Republican chieftains worship and insist that all subsequent presidents emulate. But in his second term, which coincided with Gorbachev's rise to power, Reagan flipped, making dramatic diplomatic overtures to Moscow and accepting equally dramatic proposals in turn.

Few remember, but many of the Republicans who now tout Reagan's accomplishments pummeled him at the time for "betraying" his followers and their Cold War ideology.

The pressures of those first four years—combined with the spiraling collapse of the Soviet system, which Gorbachev was keen to detect—helped bring Moscow to the table. But if Reagan had kept up his hard line (or if either of Gorbachev's ailing predecessors, Yuri Andropov or Konstantin Chernenko, had lived a little longer), the tensions would only have grown fiercer.

Ultimately, it was Reagan's reversal—the softening of his rhetoric, the willingness to negotiate, the reassurance of respect that Dobrynin had requested—that opened the way to the crucial rapprochement and the Cold War's finale.

When Republicans tell Obama to act more like Ronald Reagan, a suitable response might be: "Which one?"