Massive anti-American demonstrations in Greece have stunned the Clinton White House, compelling the president to reschedule and shorten his visit to that country. The conventional wisdom is that the outpouring of rage against the United States is either typical fare from radical leftists, still furious about Washington’s support of the military junta that ruled Greece from 1967 to 1974, or residual anger at NATO’s war against Serbia, which was overwhelmingly unpopular among Greeks.

Both factors undoubtedly play a role, but there is another reason: annoyance at Washington’s increasingly evident bias toward Greece’s long-time rival, Turkey. Greeks are especially upset that U.S. policymakers ignore or excuse Turkey’s behavior — even when Ankara’s actions include military aggression, ethnic cleansing and pervasive human rights violations.

Washington’s double standard is breathtaking. The United States was in the forefront of demands that NATO take military action against Serbia because of its ethnic cleansing in Kosovo. Yet U.S. officials have expressed only tepid and perfunctory criticism of NATO-member Turkey’s ongoing occupation of Cyprus. Turkey invaded that country in 1974, occupied some 37 percent of its territory, expelled more than 165,000 Greek Cypriots from their homes, set up a puppet republic and brought in tens of thousands of colonists from the Turkish mainland. If Ankara’s actions in Cyprus do not constitute ethnic cleansing, the term has no meaning.

The Cyprus episode is not Turkey’s only disturbing behavior. For more than 14 years, Turkish security forces waged a violent counterinsurgency campaign against Kurdish separatist rebels in southeastern Turkey. Nearly 37,000 people perished in that struggle, which only now seems to be winding down. The main Kurdish rebel group — the pro-communist Kurdish Workers Party (PKK) — clearly committed terrorist acts. But Human Rights Watch and other organizations have concluded that the Turkish military was responsible for the majority of civilian casualties. Turkey’s counterinsurgency campaign also included the forced “depopulation” of some 3,000 Kurdish villages and the razing of at least 900 villages.

Given Ankara’s track record on aggression and ethnic cleansing, Greeks cite the hypocrisy of the United States and its allies in allowing Turkish forces to participate in the war against Serbia. But Washington’s double standard regarding Turkey extends further. U.S. officials insist that NATO is an alliance of democracies and any nation wishing to become a member must have a firm commitment to democratic practices. Yet Washington said little in 1997 when the Turkish military gave an ultimatum to the country’s prime minister: resign or be overthrown. And U.S. officials do not have much to say when Turkish authorities routinely jail journalists and academics who have the temerity to suggest that there is an ethnically distinct Kurdish minority in Turkey — much less that the Turkish government ought to pursue a less repressive policy toward that minority.

In short, the Greeks are angry because it is all too evident that Turkey has become Washington’s pet ally and that Ankara can get away with murder — sometimes literally. The underlying reason for the pro-Turkish bias was expressed candidly by U.S. Ambassador to the United Nations Richard Holbrooke. According to Holbrooke, Turkey is as important to the United States and NATO in the post-Cold War era as West Germany was during the Cold War. A government that regards Turkey as such an indispensable ally is not likely to let minor blemishes like military aggression, ethnic cleansing or contempt for democratic norms preclude a close relationship.

Washington’s indulgent attitude is short-sighted as well as hypocritical. U.S. policymakers regard Turkey as a bulwark against Islamic radicalism and as a stabilizing influence in the Balkans, the Middle East and Central Asia. The first assumption is questionable, given the strength of radical Islamic elements inside Turkey; the second assumption is wholly fallacious.

Turkey shows signs of being a disruptive, revisionist power, not a stabilizing, status quo power. In addition to Ankara’s intransigence regarding Cyprus, Turkey imposed a brutal economic blockade against Armenia and has threatened to use force to settle disputes with Syria. Worst of all is Ankara’s conduct toward Greece. Turkish air force planes routinely violate Greek air space and engage in other forms of harassment, and Ankara continues to press claims to Greek islands in the Aegean. Again, the United States not only fails to condemn such behavior, it is receptive to Turkey’s dubious territorial claims.

Although there has been much press speculation about an improvement in Greco-Turkish relations as a result of humanitarian cooperation in the aftermath of the earthquakes that damaged both countries, the conciliatory actions have thus far been overwhelmingly one way. For example, Greece has dropped its opposition to Turkey’s becoming a candidate for membership in the European Union. Turkey promptly pocketed that concession but has not reciprocated with concessions on Cyprus or any other issue.

It is, of course, not Washington’s responsibility to compel Ankara to cease its offensive behavior. But the United States should at least not be Turkey’s enabler. Unfortunately, Washington’s flagrant double standard encourages Turkish officials’ inflated sense of their country’s strategic importance and may even encourage them to conclude that they can pursue aggressive measures against neighboring countries with U.S. acquiescence, if not tacit approval. The demonstrations convulsing Greece are at least partly a response to Washington’s hypocrisy. It is a message the administration should heed.