ISTANBUL, June 10 (Simon Cameron-Moore/Reuters) - Turkey can count on applause from Arab foreign ministers for championing the cause of Gaza's Palestinians meeting in Istanbul on Thursday, but some may be discomfited that Turkey has done what they have failed to do.

Turkish Prime Minister Tayyip Erdogan will open the meeting of economic and foreign ministers of the 22 members of the Arab League on Thursday, having put Gaza's plight near the top of the world agenda after an Israeli commando raid on an aid ship.

Though a non-Arab, Erdogan has become a hero to many Arabs, who admire his unbending demands that Israel lift a blockade of 1.5 million Palestinians in Gaza, submit to an international inquiry, and pay a price for the killing of nine Turks during the storming of the Mavi Marmara.

Israel says the blockade is needed to stop weapons being smuggled to Hamas Islamists running Gaza, and that soldiers only opened fire with live ammunition after being attacked.

Though Arab countries like Egypt, Jordan and Saudia Arabia have little sympathy for Hamas, Erdogan has spoken up for the group and offered to mediate in its feud with the secular Fatah faction of Palestinian President Mahmoud Abbas.

Some Arab leaders may be wary of the democratically-elected Erdogan's popularity, as it might invite unwelcome comparisons.

Powerful countries of the Arab world, namely Egypt and Saudi Arabia, are not pleased with Turkey's recent attitude, says Duygu Bazoglu Sezer, professor of international relations at Dogus University in Istanbul.

They're disturbed because it makes their countries look less effective and sensitive regarding the Palestine issue and because Erdogan is trying to become the Arab world's leader.

They're not the only ones disturbed.

U.S. Defense Secretary Robert Gates said on Wednesday that the United States is concerned at a breakdown in Turkey's relations with Israel and fears Europe's stalling over Ankara's bid for EU membership is pushing a pivotal U.S. ally away from the West.

I personally think that if there is anything to the notion that Turkey is, if you will, moving eastward, it is, in my view, in no small part because it was pushed, and pushed by some in Europe refusing to give Turkey the kind of organic link to the West that Turkey sought, Gates told reporters in London.

A Cold War ally of the West, Turkey had been largely Western facing, but under Erdogan policy has shifted to deepen ties with the former Soviet bloc and Middle East.

Critics say Erdogan's Islamist-leaning government could risk tilting too far in trying to forge stronger ties with those Middle East governments that the West doesn't trust.


ISRAEL AND IRAN

With so many powerful actors involved in the Middle East, Turkey could struggle to reclaim a leadership role in a region that it retreated from after the collapse of the Ottoman Empire.

Sezer saw Arab countries rejecting any attempt by Turkey to run their agenda with Israel.

Turkey has cast a role for itself, but I dont think that role will be accepted by others, especially Egypt and Saudi Arabia, he said.

The United States and Arab governments can at least take some comfort that it is Erdogan who has become a darling for people of the region, rather than Iranian President Mahmoud Ahmadinejad or the Hizbollah leader Hassan Nasrallah.

The meeting comes a day after an the UN Security Council voted to impose a fourth round of sanctions on Iran because of its nuclear program.

Turkey, together with Brazil, risked upsetting the United States, by brokering a nuclear fuel swap in a vain bid to head off a fourth round of sanctions against Iran.

Having voted against sanctions in order to keep the door open for diplomacy with Tehran, Turkey could use Thursday's meeting to warn the world of the dangers of pushing Iran into a corner and raise the issue of Israel's nuclear status.

Israel, like India, Pakistan and North Korea, is outside the NPT and is widely assumed to have a nuclear arsenal, though it has never confirmed or denied this.

Arab Sunni Muslim leaders have kept largely silent on the matter of sanctions against Shi'ite Iran.

But they privately express worries to Western officials over Iran's suspected nuclear ambitions and consequences of a possible Israeli strike on Iran. (Editing by Ralph Boulton)

(Additional reporting by Tulay Karadeniz and Jon Hemming)