Turkish President Recep Tayyip Erdogan’s determination to buy the Russian S-400 antimissile system in spite of American opposition and subsequent suspension of Turkey’s participation in the production program of the F-35 fighter plane have not only dealt a severe blow to the relations between the two countries, it has also raised the question of Turkey’s NATO membership. Other member states are left wondering whether Turkey is still pledged to the organization or on the way out.Turkey has been a valued member of NATO for 67 years because of its geostrategic position between Europe and Asia, it being part of the Middle East and the Muslim world and its proven military might. In the beginning, it was felt that it belonged to the secular and progressive West on the strength of the legacy of Kemal Ataturk. For the North Atlantic/European organization, the Middle East was considered as part of its larger security system. Not a few of these assumptions have been challenged in recent years.Turkey was admitted to NATO in 1952 at the height of the Cold War on the strength of its participation in the Korean War; it had been one of the first countries to answer the UN call and send troops to fight the invading north. Today, the Turkish army is the second largest of the alliance after that of America. Its purpose then had been to secure the support of the West against Soviet territorial demands following WWII. Moscow wanted to annex parts of its eastern regions and to be involved in the supervision of shipping in the Bosporus and Dardanelles straits as stipulated in the 1936 Montreux Convention. Turkey objected, received the backing of Europe and was admitted to NATO.However, NATO is not merely a military alliance; the signatories to the treaty stressed that “they are determined to safeguard the freedom, common heritage and civilization of their peoples, founded on the principles of democracy, individual liberty and the rule of law.”For many years, Turkey was a faithful ally enjoying good relations with all members who developed their economic and financial cooperation and contributed to its progress. It was accepted as an associate member of the European Union with its attending privileges.America gave it military assistance, established military camps on its territory; the huge Incirlik Air Base was put at its disposal and tactical nuclear weapons were stocked there. Within the NATO framework, Turkey participated in the development and production of attack and defense material and was taking part in the committee supervising plans to manufacture F-35 fighter planes.Nevertheless, seeds of discord appeared as early as 1974, when Turkey occupied northern Cyprus, home to a largely Turkish population, forcibly exiling 180,000 ethnic Greeks. A move condemned by the UN Security Council, demanding the immediate withdrawal of “foreign forces” while the European Committee for Human Rights accused Ankara of violating the European human rights charter. Turkish authorities replied that they were responding to a military coup led by Greek forces who had taken over Cyprus and were about to annex it to Greece; it had acted to save local Turks from being massacred. Great Britain, which maintained military camps in the island, was prevented from launching an attack to dislodge the invaders by the United States, fearful that it would create a rift in NATO and destabilize the region.Washington did impose an arms embargo on its fellow NATO member, an awkward situation for the military alliance. The ban was lifted three years later by President Jimmy Carter. In 1983, the Turkish government of Northern Cyprus proclaimed the independence of “the Turkish Republic of Northern Cyprus.” Though Turkey had acted in violation of the NATO charter, which states that “the parties undertake, as set forth in the charter of the United Nations, to settle any international dispute in which they may be involved by peaceful means... and to refrain in their international relations from the threat or use of force,” its army was still at the time the bulwark of a secular regime enjoying good relations with the West. The alliance survived and indeed Turkey sided with the US in its fight in Afghanistan after 9/11. It was from Incirlik Air Base that US planes departed to give logistic support to the troops and refuel coalition fighters over Afghanistan. Turkey also took part in the “international security assistance forces” created by the UN in 2011 to combat the Taliban.NEVERTHELESS, THE Cyprus question was still simmering. Following the discovery of large gas fields in its economic waters, Ankara demanded that their revenues be shared with Northern Cyprus, and to emphasize its determination, it dispatched in 2018 gas exploration vessels to the territorial waters of Cyprus, which is a member of the European Union since 2004. This thorny issue could lead to an international crisis and has already intensified regional tensions.The victory of Erdogan’s Islamist AKLP Party in 2002 was a watershed moment in the relations between Turkey and the United States, and conflicts of interests soon appeared. Erdogan opposed American intervention in Iraq, fearing it would lead to chaos in the neighboring country. The Turkish parliament refused to let American troops set up camps in preparation for the intervention and even forbade the use of Incirlik for the departure of bomber planes. It was a bitter blow since the US Air Force had to find more distant airfields.The rift between the two never healed, and indeed grew as Erdogan tightened his grip on Turkey. Turkey demanded the extradition of Fethullah Gulen, an Islamic Turkish thinker living in the US, accused by Erdogan to be the initiator of the failed military coup in November 2016. The US refused since Erdogan offered no proof of his allegations.A presidential system was adopted in 2017. The regime is openly pursuing an agenda based on the greatness of the Ottoman Empire and on the extremist creed of the Muslim Brotherhood. Dubbed neo-Ottomanism, a mix of religious and nationalist elements, this agenda led the president to embark on an aggressive foreign policy to assert Turkish domination in the Middle East on the basis of Islam, the common denominator of the region. It failed dismally. Only Qatar, which supports the Brotherhood, is still on friendly terms with him. Saudi Arabia and its Gulf allies, as well as Iraq, mistrust him, and Syria sees him as an enemy. Relations with Egypt were cut following the ouster of Muslim Brotherhood’s President Mohamed Morsi.The rift with America widened even more with the outbreak of the Syrian civil war in 2011. While President Barack Obama set up a coalition to fight Daesh, Erdogan let thousands of enthusiastic young Muslims transit through his country to join the insurgency, and even enabled the sale of crude from the Islamic State. He wanted to help Daesh defeat Bashar Assad’s secular regime and establish an Islamic entity friendly to Turkey, in the mistaken belief that the so-called moderate Islamic groups he was helping would later assume power. He only realized his mistake when America started backing the Kurds and their newly created SDF – “Syrian Democratic Forces” – based on of the Kurdish “People Protection Units,” the largest Kurdish armed force in Syria. Turkey brands them as a terror organization because of their ties to the PKK – the Turkish Workers Party – fighting for the independence of the Kurdish minority in Turkey. Soon, the SDF had defeated Daesh with American help and advisers had taken over the northern part of Syria along the Turkish border.Then came the confrontation with Russia following the downing by Turkish air force of a Russian Su-24 which had entered Turkish airspace for a few seconds. Moscow retaliated by imposing biting sanctions, impacting Turkish agriculture and tourism. Now at odds with the US and with Russia, Erdogan decided to side with the latter and not the former and to pursue his fight against the Kurds. He apologized and was welcomed with open arms by Putin. He was included together with Iran in the Russian-led Astana Economic Forum aiming to draw the future map of Syria – so far with no success. Turkish forces aided by pro-Turkish Islamic militias took Efrin, a vast Kurdish district near the border, after Russian troops, stationed there to support their Assad ally, moved out. (Needless to say, the Syrian president fumed impotently. After all, this is the Middle East). Some 150,000 people fled, rejoining the millions of Syrian refugees. Turkey now announced that it intended to set up a 40-km.-wide security zone on the Syrian side of their border and maintain it with the help of its army in violation of international law. Assad protested to what amounted to an occupation while vainly trying to negotiate an acceptable compromise. On July 24, Ankara announced that talks with Washington about the size of the projected security zone and the forces to be stationed there had failed.IT IS on that highly volatile background that the S-400 crisis came. America made an all-out effort to convince Turkey not to buy the Russian defense system, offering the similar Patriot system with advantageous conditions. It argued that introducing the Russian S-400 to the defense apparatus of a NATO member would in effect provide Russia with a fixed source of information on NATO capabilities and on its own, especially concerning the new F-35 fighter plane. Washington, as an added pressure, stopped training Turkish pilots on that plane in the United States. As the first components of the S-400 started arriving in Turkey, Erdogan announced that the sale would go on. Trump suspended Turkey’s participation in the F-35 project and canceled the permit previously granted to Turkey for the manufacturing of some 900 components, as well of the sale of 100 F-35s, a loss of millions of dollars for American industries.The shifting of alliances born of the downing of the Russian plane has led to a growing Turkish-Russian cooperation. The Turkstream natural gas pipeline from Russia to Turkey, temporarily halted by the Sukhoi crisis, was completed last November. A nuclear power plant also temporarily on hold for the same reason is being built in Akkuyu under the auspices of Russian Rosatom and is expected to become operational in 2023.America is in a quandary. It sees the S-400 affair as a manifestation of hostility on the part of a country it has been helping for the past 67 years, something akin to biting the hand that fed you. It left it with no choice but to cancel a lucrative deal. Still, President Donald Trump is in no hurry to go further, though there are calls in America to expel Turkey from NATO. It would benefit neither the alliance nor the United States, neither being keen to push it further in the embrace of the Russian bear. NATO Secretary-General Jens Stoltenberg, who was in Turkey last May at the height of the S-400 crisis, was at pains to stress that Turkey was a valued member and praised it for its present contribution to the fighting in Iraq and past assistance in Afghanistan and Kosovo, adding that the alliance was supporting Ankara against security threats and assisting it to defend itself through anti-missile defense systems and AWACS patrols. NATO, he said, had invested more than $5 billion in military infrastructures in Turkey, including airfields, naval installations and radar.One has to remember that the European Union is heavily dependent on Turkey to stop the flow of refugees from the region and has already paid $6 billion for its help.Turkey does not have to fear being booted out of NATO anytime soon. America has its hands full with Iran and will keep on trying to reach an honorable compromise to resume some form of cooperation. As to Ankara, it has no interest in leaving an organization which gave so much to its defense and development. It is fully aware that it is the West, not Russia, which brings in the technological investments it needs. It is aware, too, that the last 500 years have demonstrated that Russia has been a dangerous ally not to be trusted.And yet... Erdogan will have to tread carefully. In Syria and in Cyprus, events could spiral out of control, leaving Trump no choice but to take a hard line.The writer is former ambassador of Israel to Romania, Egypt and Sweden.