SYDNEY, Australia — Since the nuclear deal with Iran was announced on July 14, Republicans have attacked it with fire-and-brimstone zeal. They have called it everything from appeasement to betrayal. President Obama has fired back, arguing that opposition to the deal stems from the same worldview that led to the 2003 invasion of Iraq: “A mind-set characterized by a preference for military action over diplomacy.”

But this strain of thinking goes beyond Iraq. Although not all conservative Republicans share it, the tendency to reject diplomatic deals is rooted on the right of the American political spectrum. And while several Democrats — from Harry Truman to Henry “Scoop” Jackson during the Cold War — have embraced aspects of this hardline foreign policy, it is conservatives who are far more likely than liberals to stress confrontation over conciliation.

Since the early 1950s, many conservatives — conditioned to think in Manichean terms of absolute victory or total surrender — have opposed major peace initiatives on the grounds that they were forms of surrender and appeasement. Rather than making the world safer, they argued, such diplomatic deals weakened America’s global standing.

The antipathy toward diplomacy so often found on the right goes back to what conservatives see as the original sin of postwar diplomacy: the 1945 Yalta Conference. The meeting between Franklin Roosevelt, Winston Churchill and Joseph Stalin recognized Soviet hegemony in Eastern Europe, where the Red Army had established itself in its westward march to Germany.