When I arrived in Israel this month for meetings with thought leaders in intelligence, politics, history and security, I thought I knew most of the logistical and strategic challenges they would face in the near future. But I had a blind spot for the challenge of keeping the nation unified.Depending on how the next election cycle is handled, Israel’s esprit de corps could be its most important asset, or its Achilles’ heel.Iran’s race toward nuclear arms and its desire to turn Syria into a second Hezbollah are serious challenges facing Israel. The possible use of Iraqi and Yemini launching pads for precision-guided long-range missiles aimed at Israel adds to the menace of the Iranian threat.The urgency for Israeli national solidarity for the success of the next war has moved into the top tier of my list. A war with Iran will likely be on three fronts, with unprecedented missile attacks throughout the whole country. Even a small number of terrorists on land or through tunnels who kill or kidnap civilians or soldiers would raise the nation’s anxiety to unprecedented levels.The best way for Israel to deal with those challenges is for the next government to be one of national unity. No matter how capable Prime Minister Benjamin Netanyahu is, or what he has accomplished both diplomatically and militarily, it is unlikely that he could form a national-unity government after the March election, the third in less than a year. His path to power is most likely a razor-thin majority right-wing coalition government, a poor choice when the nation needs as much as ever to have its sense of purpose.Bibi will be prime minister through March and perhaps much longer, if there is a fourth election and his trial drags on until 2021 – a crazy scenario for a nation that could be in an unprecedented war for its survival against an Iranian regime whose Shi’ite revolutionary Islamism demands the annihilation of the Jewish state as its raison d’etre.Let’s hope that if the next election ends in another coalition paralysis, Bibi allows a unity government to form whether or not he is to be its prime minister.No one leader is indispensable for a nation’s survival, but unity of the nation is required if Israel is to win its next war and deal with its repercussions. It is hard for any nation to imagine being led by someone else after so many years, but even the United States during World War II survived and thrived after the death of Franklin D. Roosevelt, and an untested president Harry S. Truman took the reins of government.According to the Jerusalem Institute for Strategy and Security’s National Security Policy for Israel, “The most important challenge facing any government in Israel is nurturing cohesion in Israeli society; ensuring unity in the face of tests that may be posed to Israel by the violent Mideast environment.... Deterrence is based not only on sheer military might... [but] above all on the capacity to bear loss and pain both at the front lines and on the home front.”With so many potential threats looming against Israel even beyond Iran, including the possible fall of the Jordanian monarchy, a Russia that does not give Israel the freedom of the skies to strike Iranian targets in Syria, a civil war in the post-Abbas era with the emergence of Hamastan on the Jordan, a national-unity coalition government may be the secret sauce Israel needs.The writer is the director of the Middle East Political Information Network. He regularly briefs members of the Senate, House, and their foreign policy advisers, as well White House advisers.I have come away convinced that whether by design or accident, sooner rather than later, Israel could be faced with its most significant war since 1973, whether on its own terms or not.Israel has an incredibly strong and well-prepared military that is light years ahead in preparation, munitions, technology, and capabilities compared to previous wars.