Originally published under the title "Where Is the Middle East Headed?"

The Middle East has been transformed by state collapse in (clockwise from upper left) Libya, Syria, Iraq, and Yemen.

Since the Middle East events of 2011 (mislabeled "the Arab Spring"), the region has been in turmoil. The inability of the Arab statist structures to overcome domestic cleavages became very clear. Even before 2011, Lebanon, Iraq, Somalia, as well as the Palestinian Authority failed to hold together. After 2011, Syria and Yemen descended into a state of civil war. Similarly, Egypt underwent a political crisis, allowing for the emergence of an Islamist regime. It took a year for a military coup to restore the praetorian ancient regime. All Arab republican regimes were under stress. While the monarchies weathered the political storm, their future stability is not guaranteed.

Growing Islamist influence put additional pressure on the Arab states. The quick rise of the Islamic State group in Syria and Iraq was the most dramatic expression of this phenomenon that spread beyond the borders of the Middle East. Despite its expected military defeat, the ideology behind the establishment of an Islamic caliphate and variants of radical Islam remain resonant in many Muslim quarters. Therefore, the pockets containing ISIS and al-Qaida followers, as well as the stronger Muslim Brotherhood are likely to continue to challenge peace and stability in the Middle East and elsewhere.

The Sunni-Shiite divide has come to dominate Middle Eastern politics.

The Sunni-Shiite divide, a constant feature of Middle Eastern politics, has become more dominant as Iran becomes increasingly feared. The 2015 nuclear deal (the Joint Comprehensive Plan of Action) between Iran and world powers has been generally viewed in the Middle East as an Iranian (Shiite, Persian) diplomatic victory. Shiite-dominated Iraq (excluding the Kurdish region) turned into an Iranian satellite as well, while the military involvement of Iran and its proxies on behalf of Syrian President Bashar Assad in Syria appears to achieve the completion of a Shiite corridor from Iran to the Mediterranean. Iran continues its long-range missile program unabated and makes progress even in the nuclear arena within the limits of the flawed JCPOA. Its proxies rule Baghdad, Beirut, Damascus, and Sanaa, signaling increasing Iranian clout.

In contrast, the Sunni powers display weakness. Saudi Arabia (together with Sunni Turkey) failed to dislodge Assad, Iran's ally, in Syria. Saudi Arabian Crown Prince and Defense Minister Mohammed bin Salman‎ pushed Saudi Arabia into a more muscular posture, but failed to win the civil war in Yemen -- its backyard. Moreover, Riyadh has not been successful so far in strong-arming its small neighbor Qatar into dropping its pro-Islamist and pro-Iranian policies.

Egypt is an important Arab Sunni state in the moderate camp. Yet the traditional weight it has carried in the Arab world is lighter nowadays, primarily because of its immense economic troubles. Providing food for the Egyptian people is Cairo's first priority. At the same time, Cairo is fighting an Islamist insurgence at home. This situation, which leaves little energy for regional endeavors, is hardly going to change any time soon.

Israel is now an informal member of the moderate Sunni camp.

Israel is an informal member of the moderate Sunni camp since it shares its main concern -- the Iranian quest for hegemony in the region. While powerful and ready to use force when necessary, Israel, under the leadership of Prime Minister Benjamin Netanyahu, is reluctant to interfere beyond its borders.

This prudent approach is based on the understanding that Israel, a small state endowed with limited resources, lacks the capacity for political engineering in the Middle East. A growing Iranian presence near Israel's borders and the reestablishment of an eastern front might become a serious military challenge.

The disengagement of the U.S. from the Middle East, accentuated by the foreign policy of then-President Barak Obama, continues. Under Obama, the attempts to engage Syria and Iran were generally viewed as weakness, perceptions that were reinforced by the signing of the JCPOA with Iran. The obsessive campaign to defeat ISIS, started by Obama and continued by President Donald Trump, primarily helped Iranian schemes.

The new Trump administration has failed so far to formulate a coherent approach to the Middle East.

The new Trump administration has failed so far to formulate a coherent approach to the Middle East. Moreover, the gradual erosion in the U.S. capability to project force into the region amplifies the sense that America has lost the ability to play a role in regional politics.

The vacuum created by American feebleness has been filled to some extent by the Russians. The Russian military intervention in the Syrian civil war saved the Assad regime from defeat. It constrained Turkey's involvement in Syria and helped Iranian encroachment in the region.

The regional vacuum created by U.S. feebleness invites growing Russian and Chinese involvement.

We also see growing Chinese interest. The ambitious One Belt One Road infrastructure project tries to tie the Middle East to Chinese economic and political endeavors. China inaugurated its first overseas naval base in Djibouti in July 2017. Located astride a crucial maritime choke point, the military installation is symbolic of its growing confidence as an emerging global power, capable of projecting military force and directly protecting its interests in the Middle East, Africa and the western Indian Ocean.

Yet extra-regional powers can hardly change the political dynamics in the region. The regional forces are usually decisive in determining political outcomes. Moreover, Middle East history provides many examples of external actors being manipulated by regional powers for their own schemes.

Adopting such a perspective on outsiders, and in view of the deep crisis in the Arab world, it stands to reason that the relations between Iran and Turkey will be a key factor in designing the future trends in the region. They are the two largest powers and they are both ambitious and capable enough to play a serious role. Despite the historical rivalry and the dividing Shiite-Sunni religious identity that could lead to competition, it seems that they are cooperating. Turkey and Iran have discussed possible joint military action against Kurdish militant groups. Both are siding with Qatar. Both are using Islamic motifs and anti-Israel positions to win hearts in the Arab world. We may well see an Iranian-Turkish duumvirate in the Middle East, but the statist interests and the different interpretation of Islam could push the two former empires into an adversarial relationship.

Efraim Inbar, professor emeritus of political studies at Bar-Ilan University and former director of the Begin-Sadat Center for Strategic Studies, is a Shillman-Ginsburg fellow at the Middle East Forum.