WASHINGTON – When Turkish Prime Minister Recep Tayyip Erdogan addresses the United Nations this week, he likely will repeat his demand that the world body “raise the Pvalestinian flag” without acknowledging that Palestinian Authority President Mahmoud Abbas refuses to negotiate with Israeli Prime Minister Benjamin Netanyahu and Hamas leaders still call for the destruction of Israel.

For the first time since becoming a republic in 1923, Turkey has decided to become an active regional player. The decision to stretch its legs is made possible in no small part by a shrunken American footprint in the eastern Mediterranean.

Some assert that this exercise is merely an enhanced version of a trade expansion policy initiated during the 1980s. Others claim with alarm that it is an aggressive effort to restore imperial Ottoman glory with a decidedly Islamist flavor.

Whatever the reason, this so-called “Zero Problems” policy, drawn up by Foreign Minister Ahmet Davutoglu and championed by Erdogan, has been executed at the expense of Turkey’s former strategic ally, Israel, and threatens hundreds of years of friendship and peaceful coexistence between two dynamic peoples. (To be fair, Erdogan also is currently engaged in heated rhetoric with EU members Greece and Cyprus.)

It is worth noting that Turkish-Israeli ties, which flourished in the 1990s, remained strong after the Justice and Development Party’s (AKP) electoral triumph in Turkey in November 2002. Additional commercial and defense agreements were signed. Hundreds of thousands of Israeli tourists flocked to Istanbul, Antalya and Bodrum. In a May 2005 visit to Israel, Erdogan met with Prime Minister Ariel Sharon and paid his respects at the Yad Vashem Holocaust memorial. President Shimon Peres delivered an address to the Turkish Parliament in 2007 and Prime Minister Ehud Olmert visited Ankara the following year.

Cracks appeared, however, after the Erdogan government recognized Hamas’ victory in the Gaza election in 2006 and AKP officials invited the terrorist organization’s leader in exile, Khaled Meshal, to visit Ankara. The relationship suffered further in late December 2008 after hundreds of Hamas rocket attacks on Israeli towns prompted a military response. Erdogan had met with Olmert mere days before Operation Cast Lead commenced, in part to continue mediation efforts between Israel and Syria, and reportedly was furious that his counterpart kept him in the dark about the planned campaign.

Erdogan’s theatrics at the Davos World Economic Forum weeks later brought the schism into the open. Sitting on a panel with Peres, the prime minister was clearly agitated by Peres’ defense of Israel’s actions and responded, “When it comes to killing, you know this job very well.” After storming off the stage, Erdogan accused the Jewish state of committing acts of genocide. (His petulant behavior was all the more remarkable considering that Turkey has lost tens of thousands of its own citizens in a decades-old battle against PKK terrorists based in Iraq.)

Last year’s Israeli interception of the Gaza blockade-running Mavi Marmara that killed nine Turkish radicals and injured several Israeli commandos effectively doomed the political relationship. The subsequent U.N. panel of inquiry on the Gaza flotilla incident, known as the Palmer Report, found that the interception was legal under international law but that the Israeli military had used excessive force on board the vessel.

Having spent more than a year hammering through Turkey’s increasingly obedient media outlets that the Israeli action in international waters was one of “piracy” and demanding that Israel end all of its security measures around Gaza, the Palmer Report’s findings caught Erdogan off guard. He responded by trashing its conclusions, terminating all bilateral military trade, downgrading diplomatic ties and ratcheting up the anti-Israel rhetoric even further, to the point where even a clash between the two navies in the Mediterranean no longer seems out of the question.

As former U.S. Ambassador to Turkey Morton Abramowitz and Professor Henri Barkey wrote recently in the Washington Post, “Had Erdogan pushed only for an apology over the deaths of Turkish citizens in the May 2010 flotilla incident, Turkey’s actions would be understandable in the face of Israel’s unwise decision not to immediately resolve the problem. The recently leaked U.N. report on the flotilla affair sought to find a way for the sides to reconcile. Erdogan, however, is not interested in repairing the situation with Israel.”

Israel supports a Palestinian state, but lasting peace must come through negotiations that settle all outstanding issues to the satisfaction of the parties with mutual respect and security. Peace cannot be imposed; it can only be negotiated.

Whatever one thinks of President Barack Obama’s handling of U.S.-Israel relations up through this spring, his administration deserves credit for rallying opposition to Abbas’ U.N. scheme.

Obama also needs to be firm with Erdogan. While the United States recognizes Turkey’s enhanced standing in a volatile region, he should be reminded that “with great power there must also come great responsibility.” And if Erdogan carries out the once unthinkable idea of forcing America to choose between its two strategic allies in the region, the White House must send a clear signal that the Turkish leader will be the big loser.

Jason Epstein, president of Southfive Strategies, LLC, was a member of the Turkish Embassy’s public relations team from 2002 to 2007.