Prime Minister Ehud Olmert has said, at the Saban Conference and again at this week's cabinet meeting, that the objective of the Annapolis conference will be to launch negotiations that will conclude in a final-status settlement within a year. Leave aside for the moment the fact that this goal is built on short-circuiting of the road map, in the form of an Israeli agreement to negotiate despite continuing Palestinian terrorism and the failure to implement Phase I of that diplomatic blueprint. Does this approach have any chance of success? While the theory behind the current diplomatic push is fuzzy and contradictory, its essence is this: The parties are exhausted; the outlines of the ultimate agreement are clear; and an opportunity has arisen in the shared fear of a rising Iranian threat common to Israel, Arab states and moderate Palestinians. Another part of the theory is that the US has a paramount interest in leveraging this new opportunity to isolate Iran. Sometimes, indeed, it seems that while the effort to tighten sanctions against Iran continues, the Bush administration itself may have little faith in that effort's success, and diplomacy regarding the Arab-Israeli conflict has in fact become the centerpiece of the anti-Iranian effort. The idea that brokering an Arab-Israeli peace would be a setback for Iran is a valid one. Iran wants to destroy Israel, so anything that safeguards Israel's freedom and security is a defeat for Teheran. An end to the century-long Arab campaign to prevent Israel's founding and seek its destruction would indeed be a tremendous feather in the West's cap and a major defeat for the jihadi camp. It should go without saying that this is the dream of the Israeli people and of every Israeli leader. There is a problem, however, with the American theory: It suffers from a high degree of circularity. Essentially, it proposes that fear of Iran is producing an opportunity, while taking advantage of the opportunity will itself address the Iranian threat. In fact, making peace between Arabs and Israelis, as desirable as that is in any case, will not in and of itself lessen the growing danger from Iran. If anything, the arrow of causality points much more strongly in the other direction: Arab-Israeli peace depends on preventing the current Iranian regime from becoming a nuclear power. This is so because if that regime is allowed to go nuclear, all of the most radical forces in the region - from Hizbullah to Hamas to al-Qaida - will suddenly enjoy a tailwind from Teheran. For the first time, the world's most dangerous terrorist regimes and groups will have their own nuclear umbrella. The opportunity that the US has identified and hopes to take advantage of will instead be brought to a close, as Arab regimes are forced to accommodate Iran rather than the US. Accordingly, the idea of setting a deadline for wrapping up an agreement between Israelis and Palestinians is missing something as important: a deadline for turning back the Iranian threat. While advances in Arab-Israeli diplomacy may temporarily show momentum for the West and increase Iran's isolation, any fruits of this diplomacy will unravel if Iran is simultaneously allowed to go nuclear. Genuine Arab-Israeli peace means permanently giving up the quest to destroy Israel. Which Arab state would have the courage to do that at a moment when Iran is becoming the dominant regional power? Thus the process that Annapolis seeks to launch will be inherently conditional on Western success against the Iranian challenge. All nations that sincerely wish for progress toward Arab-Israeli peace must understand this. The failure to date of the US and Europe - not to mention the UN Security Council - to bring their full economic and diplomatic strength to bear against Iran first and foremost threatens the security of the entire West, including, of course, Israel. If this failure continues, the result will be a much more dangerous world, characterized by a global nuclear arms race, growing terrorism, sky-high oil prices, waning Western influence, perhaps culminating in a full-blown war. In such a world, the collapse of the Arab-Israeli peace process will be one of the lesser tragedies resulting from the West's refusal to defend itself. By the same token, if the Iranian challenge is successfully met over the year ahead, this same year could indeed become a significant one in the quest for peace.