EVER SINCE the “Arab Spring,” the Middle East has been spinning in a giddy vortex. Alongside major political and social upheavals, there has also been a dramatic shift in geo-political alignments. And although it is impossible to make a coherent forecast of what lies ahead, one thing is abundantly clear: the tried and trusted conceptual frameworks and modus operandi of the 20th century are no longer valid. For one, the 1916 Sykes-Picot agreement, according to which the borders of the nation states of the Fertile Crescent were artificially drawn after World War I, is unraveling. The countries it created are breaking up into older pre-state sectarian and tribal formations. In this inchoate and as yet unmapped 21st century Middle East, Alawites, Sunnis and Kurds are fortifying regional strongholds in a disintegrating Syria; the ethnic divide in Lebanon is widening; and in Iraq the central government has failed to heal deep Shi'ite-Sunni wounds. Nowhere is the breakdown of Sykes- Picot more evident than in the conduct of the large Kurdish tribe, who have created a de facto state in northern Iraq and are demanding similar swaths of self-determination in Syria and Turkey, too. Indeed, religious, tribal and sectarian communities striving for new forms of self-determination is one of the key signs of the times. At the end of the 20th century, scholars marveled at the resilience of the territorial state. Strong-armed “iron dictators” stifled other voices and created the impression that they could impose a national culture that would supersede and even erase the aspirations and dreams of sub-national groups. The opening decade of the 21st century and the four years that have elapsed since the eruption of the “Arab Spring” have shown the exact opposite: that in the emerging Middle East, pre-state identities – sects and tribes, religious and ethnic minorities – run far deeper than national affiliations. The cracks that opened up in the state structures and the identity politics that ensued exacerbated existing divisions, especially between Sunnis and Shi'ites. The source of the conflict between the two major religious traditions goes back to the very origins of Islam. But in the opening decades of the 21st century it took on a new urgency. The American invasion of Iraq in April 2003 and the overthrow of Saddam Hussein brought the rule of the country's Sunni minority to an end. It also led to a highly significant precedent: for the first time an Arab country headed by a Shi'ite regime. For Shi'ite Iran the revolution in Iraq was very good news. It enabled Tehran to deepen its penetration of its western neighbor, increase its economic, military and diplomatic leverage and enhance its regional standing. The already loaded relations between Shi'ite Iran and the largely Sunni Arab world became a dominant issue on the regional agenda. Arab discourse was punctuated by references to the “Shi'ite wave” and the “Shi'ite revival.” The Second Lebanon War in 2006, in which Iran's Shi'ite proxy Hezbollah fired rockets and missiles into Israel for 34 consecutive days, reinforced the impression that the Shi'ite-led rejectionist axis was growing in strength and fueled Sunni fears. The “Arab Spring” uprisings further exacerbated the sectarian struggle. The open involvement of the Shi'ite Hezbollah in the Syrian civil war from early 2013 dragged Lebanon into the crossfire.Street fighting in Tripoli and the bombing of Hezbollah bases south of Beirut blurred the border between the two countries. The situation was further complicated when radical Sunni Islamist organizations moved into Syria and Iraq, taking over large swaths of territory and intensifying a cruel and bloody conflict that has taken hundreds of thousands of lives and created millions of refugees. “The Islamic State of Iraq and the Levant,” variously known as ISIL or ISIS, which established itself in western Iraq and then swallowed up parallel territory on the Syrian side of the border, is both symptomatic of the 21st century Middle East and reflects its new goals. It only gathered momentum because of the chronic weakness of the regimes in Baghdad and Damascus. But it draws inspiration from an idealized vision of the past, and strives for the establishment of a single Islamic Caliphate to replace the nation states, which it sees as perpetuating inter-Arab divisions and serving Western interests. At the same time, ISIS stands at the center of a much wider struggle, a clash of civilizations on two parallel levels: Western civilization against the Muslim world and, within Islam, the Sunni majority against the Shi'ite renaissance led by Iran. Thus, in the heart of the 21st century Middle East, there is a sovereign space supported by the economic capabilities and ideological fervor of a terrorist organization intent on changing reality. That is a recipe for chronic regional instability and also poses a serious threat to global security. These shifting Middle Eastern sands have also been affected by significant changes in great power attitudes to the region. Indeed, another key symptom of the 21st century Middle East is America's hesitant and inconsistent policy. There have been many explanations for this, from forecasts of a significant reduction in American dependence on Middle East oil and gas to global power shifts, leading the US to prioritize southeast Asia over the Middle East. Be that as it may, the Obama administration's reliance on conciliatory diplomacy sent a loud message of weakness across the region and encouraged radical forces and states seeking hegemony to set the pace. The American decision in September 2013 not to take military action against Bashar Assad's regime in Syria, after its flagrant use of chemical weapons, was a watershed moment: it violated a code of unwritten understandings and undermined America's regional standing. At the same time, Russia has unquestionably enhanced its standing in the region. Its involvement in Syria, its cooperation with Iran and the strengthening of its ties with Sunni states point to an assertive policy designed to restore its once dominant role. China's slow and gradual penetration of regional geopolitical alignments is also having an effect. Even if it is premature to speak of a changing of the guard, it is clear that both state and non-state actors in the region are reevaluating their positions in a way that highlights the fragility of regional power structures and the ephemeral nature of political alliances. The state best able to read the changes was the Islamic Republic of Iran. With a savvy new leadership under President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif since August 2013, it clearly identified the new trends and acted accordingly. It set as its chief goal saving Iran from the economic chaos left by the previous president Mahmoud Ahmadinejad. Within a short space of time, Iran was able to escape from crippling economic and diplomatic isolation and to become a much wooed player in the diplomatic arena. This without giving any clear guarantees with regard to retreat from its military nuclear aspirations. For all these reasons, the Middle East is deep in the throes of major geo-political transition. For all the main protagonists, this demands fresh thinking and a new set of policy tools. For Israel, the 21st century Middle East poses a real challenge. Given the lack of a clear picture of the emerging balance of power, the multiple orientations and the shifting alliances, it seems that pragmatism based on the adage “the enemy of my enemy is my friend” is gaining genuine traction. Israel could find a common denominator with countries like Saudi Arabia, Kuwait, the UAE, Jordan, Egypt and Morocco which, like Israel, view with deep concern Iran's march toward nuclear power and are also declared foes of ISIS. On the Palestinian question too, the 21st century Middle East demands decisions. On the one hand, it seems that under the pressure of events, the Israeli-Palestinian conflict has been shunted into a corner. Moreover, it is now clear that it does not provide the golden key to all the region's problems, as many argued during the 20th century. On the other hand, the events of the past several weeks underscore that in this highly volatile 21st century Middle East, the Israeli-Palestinian conflict could easily be drawn into the forefront of a religious-cultural struggle. Israel needs to find the right tools to act to ensure that that does not happen. Prof. Uzi Rabi is the director of Tel Aviv University's Moshe Dayan Center for Middle Eastern and African Studies