Imagine President-elect Biden standing before two doors that represent the Middle Eastern quandary he faces. Which he chooses will color his administration and have a historic impact on the world’s most boobytrapped region.One door is marked “Return to Obama’s Iran Nuclear Deal.”The other is labelled “Build Upon Trump’s Abraham Accords.”Literature is littered with confounding two-door parables and allegories, from Jesus’ Sermon on the Mount, where the choice is between the wider or the more narrow and difficult road, to Frank R. Stockton’s 1882 short story, “The Lady, or the Tiger?” where two soundproofed doors lay before the lover of the king’s daughter.As it is with most of these tales, there are perils in any path.Democratic party politics and campaign promises would suggest that President-elect Biden move quickly toward a return to the nuclear agreement, known as JCPOA, a signature achievement for the man who picked him as vice president. President Trump withdrew from that agreement in May 2018, having called it “the worst deal ever.” The wiser course would be to move slowly, cautiously and with trepidation toward the Iran door, recognizing how much has changed in the Middle East in the four years since President Obama left office.The Obama deal, which never was blessed by congressional vote, didn’t address Iran’s regional misbehavior or its ballistic missile and advanced weapons delivery development, which negotiators left for a later day.Yet precisely such Iranian advances were on display in the September 2019 Iranian cruise missile and drone strikes on Saudi oil fields and then its ballistic missile attacks on U.S. military positions in Iraq on January 8, 2020, in answer to the drone attack that had killed Iranian General Qasem Solemani five days earlier.Beyond that, today’s Iran is unlikely to rush back into to compliance with its earlier agreement in the run-up to its June elections, where the hardliners are determined to further marginalize so-called moderates. Having accumulated more enriched uranium and installed more advanced centrifuges than JCPOA would allow, Iran’s leaders won’t abandon those gains easily.Much as they may want an easing of economic sanctions against them, Iran’s hardliners also want more: compensation for all they lost economically over the past four years because of renewed U.S. sanctions. Unsaid is that each day provides them more time to develop their nuclear capabilities further, either as leverage for future talks or making inevitable their nuclear weapons breakout.The assassination in Iran of the country’s top nuclear scientist on November 27, blamed in the country on Israel and the U.S., has further inflamed tensions and requires some response. In a sign of Iran’s hardening mood, the government just today executed dissident Iranian journalist Ruhollah Zam.So, there’s no easy path to a good deal. President Biden is unlikely to provide the fast relief and compensation Iran demands. Iran is unlikely to return to the agreement’s strictures unless it gets what it wants, and until then it won’t address issues outside the existing agreement that have become more urgent.That leaves Door Number Two.This is the one President-elect Biden should walk through as soon as he enters office. President-elect Biden himself has indicated that this could be the one Trump foreign policy achievement he would wish to build upon.President-elect Biden praised the accords from the campaign trail before they were signed at the White House this September by Bahraini, Israeli and UAE leaders. Morocco this week joined the U.S.-brokered agreement with Israel, after Sudan had done so in October. As Axios reported this week, President-elect Biden could leverage this Arab-Israeli momentum of the agreements, but he would do so differently than Trump.”He wants to use that dynamic to reflect some positive momentum back into the Israeli-Palestinian deal,” said Dan Shapiro, the former U.S. ambassador to Israel under Obama.Most crucial to watch is Saudi Arabia. Conventional wisdom has it that President-elect Biden, who has said he would reassess relations with Riyadh, will create greater distance and sharpen the focus on Saudi Arabia’s remaining human rights failings.Yet Riyadh has a vote here as well.Should King Abdullah and Crown Prince Mohammed Bin Salman act to release the high-profile women’s rights activists who remain in prison, should they repair relations with Qatar to end a three-year confrontation through ongoing Kuwaiti moderation, and should they further liberalize relations to Israel, the atmosphere could improve considerably.The assassination by Saudi government agents of journalist Jamal Khashoggi in October 2018 remains a toxic impediment, but Riyadh has the potential to change that context dramatically.Just as the UAE leveraged its agreement with Israel to stop Israel’s annexation of the West Bank, a Saudi deal to join the accords under a Biden administration could be linked to the two-state solution with the Palestinians. There’s a larger reason for President-elect Biden to choose Door Number Two, and that is as a basis for Mideast institutional and strategic change.The little noticed seventh paragraph of the Abraham Accords states, “The Parties stand ready to join with the United States to develop and launch a ‘Strategic Agenda for the Middle East’ in order to expand regional diplomatic, trade, stability and other cooperation.” Add Egypt and Jordan, countries that already have peace deals with Israel, and there’s a shot at modernist, moderate Mideast coalition of countries focused on future opportunities rather than the settling of old scores.From that basis, one could encourage the sort of economic and security institutions and integration that unlocked European potential after World War II. Even today, those institutions haven’t achieved the “Europe Whole and Free” that was President George H.W. Bush’s dream, with Russia and others remaining outside.However, no one could argue that Europe would have been better off without partial solutions. There’s also an urgent need to provide an alternative strategic future to those being offered by Iran, Turkey, Russia and China. Better yet if that strategic shift is accompanied by expanding individual freedoms, increased opportunities for youth and women, and reduced inter-religious tensions. The more these changes bring about personal and economic opportunity in the region, the more Iran’s population will want to benefit from them. Returning to President-elect Biden’s two-door predicament: the best way to improve his chances at a lasting Iran solution may be through the back entrance of the Abraham Accords. Frederick Kempe is a best-selling author, prize-winning journalist and president & CEO of the Atlantic Council, one of the United States’ most influential think tanks on global affairs. He worked at The Wall Street Journal for more than 25 years as a foreign correspondent, assistant managing editor and as the longest-serving editor of the paper’s European edition. His latest book – “Berlin 1961: Kennedy, Khrushchev, and the Most Dangerous Place on Earth” – was a New York Times best-seller and has been published in more than a dozen languages. Follow him on Twitter @FredKempe and subscribe here to Inflection Points, his look each Saturday at the past week’s top stories and trends.For more insight from CNBC contributors, follow @CNBCopinion on Twitter.