In the end, crazies on both sides will fail. Key figures in Tehran and Washington will have no choice but to recognize that reconciliation will bring enormous strategic benefits. It is a classic win-win situation. Iran finds a way out of its isolation and an escape from crushing sanctions. The United States guarantees a nuclear-weapon-free Iran and gains a potentially valuable partner in the fight against radical Sunni insurgents in Syria, Lebanon, Iraq and Afghanistan.

Hawks in Washington are also girded for battle. At a hearing a few weeks ago, members of the House Foreign Affairs Committee bombarded Kerry with denunciations of the deal, laced with cliches that reflected mind-numbing ignorance of Iran, the Middle East and the diplomatic process. Important members of Congress are grasping desperately for ways to block this detente.

Both of the key figures behind this breakthrough, U.S. Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif, have had trouble selling their deal to hard-liners at home. Iranian radicals have reason to fear peace. There is every prospect that a sanction-free Iran could thrive, especially if its governing system evolves in ways that allow the hugely talented Iranian diaspora to return home and contribute to national development. A growing middle class always leads to increasing pressure for democratic governance. That is why Iranian hard-liners dread reconciliation.

The most important geopolitical shift of 2014, however, will be the easing of hostility between the United States and Iran. This process began with the historic agreement the two countries signed in November. It is to be the first in a series of accords aiming to ensure that Iran will never produce nuclear weapons and, as a result, be welcomed back into the community of nations.

There is plenty to anticipate: China and Japan may become more aggressive and provocative over the disputed Diaoyu/Senkaku Islands, contributing to instability in East Asia. Radical fundamentalists will wage war from new bases in Mali, Libya and Syria. Turkey may become more polarized and fail to recover the promising role it played in regional politics until a couple of years ago. Nationalist and far-right political parties will gain strength in Europe. President Barack Obama’s decision to approve or reject the massive Keystone oil pipeline from Canada to the Gulf of Mexico will profoundly affect global energy markets. If King Saud dies — he will turn 90 this year — Saudi Arabia will be racked by an intense struggle over succession and the direction of the kingdom.

Not to be underestimated in the Washington debate is the influence of U.S. corporations, which see enormous opportunities in Iran. Oil companies would be obvious beneficiaries of reconciliation. Aerospace companies are salivating at the prospect of a large nation whose airplanes are in need of replacement. The pharmaceutical industry sees great possibilities in Iran because of its booming market and lack of specialized medicines. All are quietly lobbying for normalization.

Outrage over the prospect of U.S.-Iran reconciliation is based largely on emotion. Iran and the United States have inflicted terrible blows on each other, and the legacy of this history has proved maddeningly difficult to overcome. In 2014 the anger these countries feel toward each other will be moderated by strategic logic.

Saudi Arabia and Israel are working intently to block this peace process. Many of the members of Congress who bloviated at the Foreign Affairs Committee hearing sounded as if they were reading index cards prepared by pro-Israel lobbyists. This is the beginning of a major campaign in Washington aimed at blocking a U.S.-Iran deal. It will be highly reminiscent of efforts to block reconciliation between the U.S. and China 40 years ago and will fail, just as those efforts did.

When the U.S. shocked the world by extending a hand of friendship to China, two important American allies became suddenly apoplectic. Japan was terrified, and Taiwan entered panic mode. A series of reassurances, including a strengthened U.S. military commitment to Taiwan, did not resolve these doubts but allowed the United States to proceed in spite of them.

China in the 1970s was in a situation comparable to Iran’s today: marginalized from the world system despite its size, history, culture and influence. Such isolation is always destabilizing, since — as President Lyndon Johnson memorably said, it is always better to have a rival “inside the tent pissing out than outside the tent pissing in.”

Japan and Taiwan have seen that their fears of China’s emergence from isolation were unwarranted. Will Saudi Arabia and Israel follow the same path, ultimately recognizing that Iran’s return to normality might not be so bad and could even have benefits? Saudi Arabia is too trapped in its narrow paradigm to take advantage of regional shifts. Israel may be more adroit. It has a long history of cooperation with Iran, and strategic logic dictates that this resume.

Despite their evident differences, Israel and Iran are logical partners. They have cooperated fitfully over the years, most recently in the 1980s, when they faced common enemies in Iraq and the Soviet Union. Today they both view Sunni radicalism as a major threat. They share a deep suspicion of Arabs. If 2014 does indeed turn out to be the year the United States begins dealing normally with Iran, Israel could follow — but probably only in the post-Netanyahu era.

Imagining the future of Middle East politics after a U.S.-Iran rapprochement is tantalizing. First, however, the current interim accord — signed not just by the United States and Iran but also by Britain, France, Germany, Russia and China — must be transformed into a long-term treaty that will end Western sanctions and guarantee that Iran never produces nuclear weapons. Decisive progress will be made toward such a treaty in 2014. Enemies of peace in Tehran and Washington will not be able to derail it.

This geopolitical year will reach a climax in December with the awarding of the Nobel Peace Prize. As usual, there will be a host of worthy candidates, from Edward Snowden to Pope Francis. In the unlikely event that North Korea embraces pacifism, the prize will have to go to Dennis Rodman. But if peace breaks out between Washington and Tehran, Kerry and Zarif will have richly earned it.