For more than half a century, relations between Israel and Turkey have provided a degree of stability in the turbulent politics of the Middle East. Turkey was among the first majority-Muslim states to recognize Israel in 1948, and the two countries have profited from bilateral trade and military cooperation ever since. Unfortunately for Israel, things are changing.

It's not that current tensions between them will destroy their commercial relationship. Turkey remains Israel's top trade partner in the region. Nor is it that Turkish Prime Minister Recep Tayyip Erdogan's Justice and Development Party (AKP)-led government will move Turkey into some sort of anti-Israeli alliance with Iran and Syria. Turkey remains a member of NATO. And though accession talks on European Union membership are going nowhere, neither side wants to abandon efforts to bring Turkey and Europe closer together.

Yet, there's a change underway in Turkey's regional role, a shift rooted in the country's bitter internal politics, and it's not one that Israel will like. Erdogan and the AKP have seen their popularity eroded over time as the party's battle with Turkey's secularist establishment in the military, business community, and media has polarized the political class and dominated the country's agenda. But like so many leaders over time and around the world, Erdogan has discovered that foreign-policy accomplishments that raise a country's international profile can bolster a government's standing at home.

Recent international developments have added to Turkey regional clout. The U.S. regional presence is waning as U.S. troops are rapidly withdrawn from Iraq. Europe is too fully occupied with problems within the Eurozone to take up the slack as Washington redeploys. Regional players like Egypt and Saudi Arabia are distracted to some degree by questions of political succession. It will be years before Iraq's government has the self-confidence to play its traditional regional role. Though Iran's government has forced the opposition off the streets, the turmoil of the past year has done lasting damage.

This leaves Turkey in a strong position. It's one of very few countries with influence in both Washington and Tehran. Expectations for robust economic growth -- the Organization for Economic Cooperation and Development (OECD) forecasts an average of 6.7 percent per year between 2011 and 2017 -- bolster the government's self-confidence and the country's reputation as a rising regional powerbroker. 

This is bad news for Israel. At Davos in January 2009, Erdogan won widespread praise among critics of Israel by storming off stage following a heated exchange over Gaza with Israeli President Shimon Peres. This spring, Turkey burnished its geopolitical credentials by joining Brazil in a plan to end the international standoff over Iran's nuclear program -- and in voting no on U.S. and European-sponsored U.N. sanctions on Tehran. When an Israeli raid on a flotilla of ships trying to break a blockade of supplies to Gaza killed nine Turkish activists last month, Erdogan again won international applause by denouncing the attack as a "bloody massacre."

The risk is real that Erdogan will make good on threats to cut off diplomatic relations with Israel. There's not much Israel can do about it, and officials in Tel Aviv are mainly downplaying the problem to avoid making matters worse for economic relations. But they know well that Erdogan is looking to play a higher-profile, more independent role in Middle East politic -- and that Turkey is a friend that Israel can ill afford to lose.

Ian Bremmer is president of Eurasia Group and author of The End of the Free Market: Who Wins the War Between States and Corporations?