President Donald Trump’s willingness to criticize America’s traditional allies has generated a fierce backlash. Members of the infamous Blob, the foreign policy establishment, have united to defend virtually every member of every alliance.

No doubt, cooperation to advance shared interests is advantageous. However, that does not require one-sided peace guarantees to nations capable of defending themselves. And it makes no sense to ally with a country that does not advance U.S. security. Like Turkey.

Ankara has long enjoyed a reputation for being strategically important, anchoring Europe’s southeast, limiting Soviet advances into the Mediterranean through the Black Sea and into the Middle East overland. The U.S. still uses Incirlik and Izmir Air Bases to extend its military reach. Ankara has been held up as a model Islamic democracy.

Even during the Cold War, NATO paid a high price for Turkey’s inclusion. Authoritarian, military-dominated governments in Ankara enforced a ruthlessly secular public space; there were several coups, hard and soft. In 1974, Turkey invaded and partitioned the Republic of Cyprus. War almost erupted with Greece and for a time Congress barred arms sales to Ankara. With the collapse of the Soviet Union, Ankara became a regional guardian without serious duties, while its unstable, military-dominated coalition politics and weak economy didn’t look like much of a model for anyone.

The 2002 victory of Recep Tayyip Erdogan’s Justice and Development Party (AKP) transformed Turkey. Originally the AKP presented itself as responsibly religious, pro-Western, and liberal, eager to democratize Turkish society, exclude the military from politics, and join the European Union.

However, by the end of the decade, Erdogan and his party had immersed themselves in corruption and initiated authoritarian rule. His commitment to Islam turned harsh and political. Rule of law, individual liberties, and democratic procedures all were sacrificed to enhance regime power. The 2016 attempted coup was Erdogan’s Reichstag fire, justifying the brutal crackdown and purge that he’d long wanted and may have planned. Last year, for the first time, Erdogan tampered with the actual vote, forcing a rerun of the Istanbul mayoral race, which his party ended up losing twice. Next time he may be more desperate—and simply steal the election.

The cumulative impact has been to destroy what was always a flawed and limited democracy. The group Freedom House rates the country as not free. The State Department points to “reports of arbitrary killings; suspicious deaths of persons in custody; forced disappearances; torture; arbitrary arrest and detention of tens of thousands of persons,” and that’s just the start.

All of which has undermined NATO. The Europeans take democracy more seriously than during the Cold War. Indeed, they justified the alliance’s post-Cold War expansion as a means of integrating the former communist states of Central and Eastern Europe into the West. The allies also perceive Russia’s slide backward into authoritarianism as part of its menace.

Even more problematic for NATO is Ankara’s increasingly independent and hostile foreign policy. Russia is Europe’s only conceivable serious adversary. Yet Erdogan has become the equivalent of a fifth columnist, more likely to support Moscow than Brussels.

His policy toward Russia was irresponsibly reckless when, five years ago, Ankara shot down a Russian warplane operating in Syria for briefly straying into Turkish airspace. Had war erupted, Washington would have been expected to confront nuclear-armed Russia.

Erdogan then staged a dramatic policy pirouette and joined with Moscow to manage the denouement of the Syrian civil war. Moreover, Ankara decided to purchase the S-400 air defense system, triggering an administration cut-off from the F-35 program and congressional demands for economic sanctions. The Russian and Turkish governments have still ended up on opposite sides in the fight over opposition-controlled Syrian territory, Libya’s civil war, and the growing conflict between Armenia and Azerbaijan. Nevertheless, they so far have maintained their political bonds.

Indeed, Ankara’s allegiance to NATO looks a lot like Italy’s pre-World War I membership in the Triple Alliance. When armies started marching, Rome refused to honor its promises and eventually entered the war on the other side (bribed by the Entente with promises of Austro-Hungarian territory). How likely is Turkey to declare war on Russia to help defend, say, Estonia?

This factor alone warrants ejection of Ankara from the transatlantic alliance. However, Turkey’s involvement in Syria is not just a problem of cooperation with Moscow. During the early years of the civil war, the Erdogan government allowed the Islamic State free transit across the Turkish border; Turkish intelligence is believed to have directly assisted the group. Moreover, Erdogan family and staff members may have profited through trade with ISIS. Ankara also launched two invasions targeting Washington’s Kurdish allies, which led the ground assault on the Islamist movement’s Syria-based “caliphate.” Turkey employed Islamist Arabic forces, which committed ethnic cleansing and other atrocities against the Syrian Kurds.

Now Ankara is threatening war against fellow NATO members and prospective EU partners. Perhaps the most enduring dispute is over control of Aegean Sea waters. Greek islands near Turkey greatly restrict the latter’s sovereignty over areas that Ankara considers to be its own. Air and naval confrontations between Greece and Turkey are routine.

Moreover, Ankara continues to occupy much of Cyprus 46 years later. The presence of undersea oil and natural gas created a new dispute, leading to naval clashes between Turkey and the internationally recognized Cypriot government. Ankara is promoting energy exploration in areas claimed by the Turkish Republic of Northern Cyprus, recognized only by Turkey. Israel also is involved, working with Cyprus and Greece. Turkey’s relationship with Israel remains poor, and the Erdogan government recently ignored U.S. objections to meet with leaders of Hamas.

Ankara entered Libya’s continuing civil war on the side of the Tripoli-based Government of National Accord, from which Turkey extracted a maritime boundary agreement giving the latter energy development rights in waters claimed by Cyprus and Greece. Ankara broke the United Nations arms embargo and safeguarded its weapons shipments with a naval escort, which led to confrontations with Greek and French ships deployed to enforce the ban.

Ongoing ground combat in Libya could trigger a larger conflagration. Ranged against Turkey are France, Saudi Arabia, the UAE, Egypt, and Russia. Much could go wrong. Imagine an exchange of fire between American allies, with Russia tossed in for good measure. Most everyone would see Washington as the inevitable defense backstop, expected to go to war over some damn fool thing in the Mediterranean, to paraphrase Otto von Bismarck.

Finally, Turkey appears poised to intervene in the burgeoning conflict between Armenia, backed by Russia and Iran, and Azerbaijan over Nagorno-Karabakh, Azerbaijani territory largely populated by ethnic Armenians, seized after a lengthy conflict that ended in an uneasy ceasefire in 1994. Ankara subsequently helped train the Azerbaijani armed forces; in the latest flare-up it has been accused of shooting down an Armenian aircraft and introducing Syrian mercenaries in the fighting. The claims are unverified, but Turkey has publicly backed Baku, promising weapons and training.

These many seemingly isolated actions reflect an increasingly aggressive Turkish foreign policy. In his speech last Thursday to Turkey’s National Assembly, Erdogan suggested a far-reaching revisionist agenda: “There is no chance left for this distorted order, in which the entire globe is encumbered by a handful of greedy people, to continue to exist the way it currently does.” He also dismissed the effectiveness of outside pressure: “those who ignored our country in the region for years—and confronted us with maps and demands that would imprison us into our coasts—first tried the language of threat and blackmail after the steps we took.”

So Ankara no longer is the perceived ally of old. With the Cold War over, nothing requires the U.S. to ignore the autocratic elephant that was always in the room, even during the Cold War. Worse are the divergent security interests. No one in the West knows how far Turkey is prepared to push. If Ankara ends up in a shooting war with someone, including Russia, Europe and the U.S. could be dragged along.

Erdogan long ago dissipated any reservoir of trust with other Western powers, but some analysts advocate waiting for him to leave the political scene. However, at age 66 he could rule for another decade or more. Moreover, both his Islamism and nationalism enjoy strong domestic support; antagonism toward the West and especially America is strong. Even a more democratic regime would not be inclined to yield on important geopolitical questions. For instance, over the last decade the expansive maritime doctrine known as “Blue Homeland,” seeking control over waters claimed by Greece, Cyprus, Egypt, and Israel, has gained widespread support.

Out of disappointment rather than anger the U.S. should disconnect militarily from Turkey, freeing both countries to act as they believe necessary, while preserving a strong mutual diplomatic presence. At the very least Washington should remove nuclear weapons from Turkish bases and reconsider arms sales to Ankara. Moreover, NATO should review Turkey’s status. Easing Ankara out of the transatlantic alliance would improve Western security.

Most Washington policymakers treat alliances like diamonds, believing them to be forever. Yet whatever Erdogan’s political future, Turkey is likely to remain estranged from America and the West.

Which means Washington needs a more realistic policy toward Ankara. The U.S. should collaborate with the latter when possible and confront it when necessary. Most important, the next administration should stop pretending that Turkey is an ally, let alone a reliable one.

Doug Bandow is a senior fellow at the Cato Institute. A former special assistant to President Ronald Reagan, he is author of Foreign Follies: America’s New Global Empire.