Democracies have an unfortunate record of falling prey to the myth of the moderates. Confronting unfriendly regimes, they perceive powerful, moderate elements where none in fact exist. As the Obama administration moves to open a dialogue with Teheran, it would be wise to recall the lessons of history and place little faith in the influence of Iranian reformists. Consider this: An authoritarian state appears poised to dominate a region of paramount strategic importance. The democracy that has sustained a balance of power in the region grapples with how to respond. Does this sound familiar? Yes - the US and Iran in 2009, and also Great Britain and Germany before the First and Second World Wars. At both historical junctures, Great Britain let the myth of the moderates lead it astray. As Europe lurched toward war in July 1914, the British government turned to German moderates in the hope of averting a military conflagration. For a time, Edward Grey, the British foreign secretary, believed that civilian leaders like chancellor Theobald von Bethmann-Hollweg could serve as a counterweight against bellicose elements within the German regime. This belief was unfounded. In reality, Germany's civilian leadership was powerless to stop the march to war. Moreover, German diplomacy deliberately broadcast the pacific inclination of civilian leaders in the hope of obtaining British neutrality. Seeking to enlist German moderates was not only a fool's quest, it delayed the one British action that might have convinced Germany to step back from the precipice - issuing a public pledge to defend Belgium. Nazi Germany offers a similar, cautionary tale. Shortly after Hitler took power in 1933, many within the British government became convinced that the Nazi regime was divided between extremists and moderates. The latter were thought to desire peaceful and economically beneficial relations with Great Britain. This gave the British government hope that by empowering the moderates, a grand bargain could be struck with Germany, and its ambitions sated. Ultimately, the influence of the Nazi moderates proved illusory. The British government badly misunderstood the inner workings of the Third Reich. Nazi moderates held little sway over decisions of war and peace. These were decisions which rested with Hitler alone. Additionally, London was deceived: The Nazis played up the split between extremists and moderates for British consumption. The ruse worked. Convinced that Nazi moderates were a potential force for restraint, Great Britain was slow to move against Hitler. When confronting Iran, the Obama administration must be vigilant against reprising the myth of the moderates. To be sure, US policymakers are not naÃ¯ve. But neither were British officials in 1914 or 1933. British belief in German moderates was not mere wishful thinking, but stemmed from faulty analysis. Because Germany's political system in both periods lacked transparency, information concerning regime dynamics was limited. This dearth of information - which in turn facilitated German subterfuge - led the British government to imagine potent forces of moderation. Iran appears ripe for a similar misperception. Reformists evince an interest in rapprochement with the US. For policymakers in Washington, it will be tempting to place the reformists at the center of any strategy for halting Iran's nuclear program. After all, they represent a potential ally inside Iran against hard-liners like President Mahmoud Ahmadinejad. Yet, Iran's actual decision-making process is opaque, and the influence reformists wield is deeply uncertain. They may have little ability to thwart Iran's acquisition of nuclear weapons. They may even believe that Iran is entitled to them. If the US relies on Iranian reformists to generate internal pressure against nuclear arms, it risks grasping at straws. Dialogue with Teheran is more promising than the alternatives - accepting an Iranian nuclear capability or launching a preemptive strike. However, the US must move forward with no illusions. Reaching out to reformists should be a peripheral element of US strategy. The core must be convincing the real power holders - the Guardian Council - that Iran's interests are better served by eschewing nuclear weapons. This will require carrots and a willingness to use sticks. When considering punitive actions, the Obama administration should be particularly wary of Iranian efforts to play up the influence of the reformists. History demonstrates that this is a delaying tactic used by non-transparent regimes. Engage Iran, but beware the myth of the moderates. Otherwise, the United States will repeat Great Britain's strategic blunders. The writer is completing a book at Princeton University on how democracies cope with rising powers. He is also the author of Japan's Security Strategy in the Post-9/11 World: Embracing a New Realpolitik (Westport, Conn: Praeger, 2006).