ISTANBUL (Reuters) - Time was that Turkish President Tayyip Erdogan dedicated large parts of his speeches to condemning Syrian leader Bashar al-Assad for atrocities against his people, calling for his ouster and urging greater support for the rebels fighting him.

Turkish army tanks and military personal are stationed in Karkamis on the Turkish-Syrian border in the southeastern Gaziantep province, Turkey, August 25, 2016. REUTERS/Umit Bektas/File Photo

Now, as Syrian government forces capture swathes of eastern Aleppo, threatening to crush the opposition in its most important urban stronghold, Assad and the battle for what was once Syria’s biggest city get little more than passing mention.

NATO member Turkey has been one of the main backers of Syria’s rebels since early in the near six-year war.

But rapprochement with Russia, one of Assad’s main allies, frustration with U.S. policy, and an overriding concern about securing its borders against Kurdish militia fighters and Islamic State have seen Ankara scale back its ambitions.

“At the moment, Turkey’s foreign policy in Syria is hostage to Russia. Russia controls the air space and Turkish soldiers are 30 km inside Syria,” said Behlul Ozkan, assistant professor in international relations at Marmara University in Istanbul.

“Turkey needs to be in agreement with Russia on every step it takes in Syria,” he said, or Turkish troops would be exposed.

In a speech on Tuesday, Erdogan condemned what he said was the failure of the United Nations in Syria and cast Turkey’s incursion in August, when it sent tanks, fighter jets and special forces over the border, as an act of exasperation.

“Close to one million people died in Syria, and they continue dying. Where is the U.N.? What are they doing? We kept saying ‘patience, patience, patience’ but could not take it any more and entered Syria,” Erdogan said.

“We are there to bring justice. We are there to end the rule of the cruel Assad, who has been spreading state terror.”

But Turkey’s “Operation Euphrates Shield” was not about battling Assad. It aims to sweep Islamic State from a roughly 90-km (56-mile) strip of the Syrian border and prevent Kurdish militia groups from seizing territory in their wake.

Tuesday was the first time in almost a month that Erdogan had mentioned Assad by name in a major public address, according to a review of his recent speeches published on the presidency website. He made no direct reference to events in Aleppo.

A senior official from one of the Turkmen rebel brigades backed by Turkey said some 60 percent of Turkmen fighters pulled out of Aleppo in August to take part in Euphrates Shield, withdrawing from front lines against Assad’s forces.

“Of course that withdrawal had an impact. If those groups had stayed, perhaps Aleppo could have resisted more,” said the official from the Muntasir Billah Brigade, although he doubted it would have changed the course of the battle.

“They did not have much of a chance as their weapons are limited - machine guns and Kalashnikovs - while the regime and Russians have used everything from barrel bombs to warplanes,” he told Reuters from the Turkish border town of Gaziantep, a rear base for some of Syria’s rebel forces.

RUSSIAN RAPPROCHEMENT

Russia has been helping forces loyal to Assad try to take back full control of Aleppo by providing training, equipment, advice and intermittent air support.

Just over a year ago, Turkey shot down a Russian fighter jet over Syria, prompting a breakdown in ties that was only resolved in August after Russian President Vladimir Putin hosted Erdogan in St Petersburg.

The rapprochement has not changed Ankara’s position that Assad must go to restore peace in Syria, Turkish Deputy Prime Minister Numan Kurtulmus told Reuters on Saturday.

But Erdogan has spoken with Putin at least twice over the past week, agreeing to try to resolve the humanitarian crisis in Aleppo and “coordinate efforts against international terrorism”, officials in his office have said.

Foreign Minister Mevlut Cavusoglu also made a surprise visit to regional rival Iran, another key Assad ally, at the weekend, discussing cooperation in Syria with President Hassan Rouhani.

“The government does continue to criticize the brutal targeting of Aleppo by Assad and his allies, Russia and Iran, but it has seen that the rhetoric does not have much influence,” said Can Acun, a researcher at the SETA think-tank in Ankara.

“It is trying to achieve results through shuttle diplomacy with Iran and Russia through its bilateral ties but so far there haven’t been any meaningful positive results,” he said, adding that the international community was “turning a blind eye”.

“Turkey does not have much of a capacity in the current equation to get results on its own.”

The level of continued support from the rebels’ other backers, including the United States and Gulf, is uncertain.

President-elect Donald Trump has signaled opposition to U.S. support for the rebels, indicating he could abandon them to focus on fighting Islamic State.

Qatar’s foreign minister told Reuters this week Doha would continue to arm them even if Trump ends U.S. backing, but would not on its own supply the shoulder-fired missiles they want to defend against Syrian and Russian warplanes.

For its part, Turkey’s focus is squarely on ensuring that the Turkmen and Arab rebels it backs secure the 90 km strip of territory south of its border and prevent Kurdish militias from joining up cantons they already control on either side. Ankara fears such a move would stoke Kurdish separatism at home.

Their immediate challenge is securing al-Bab, an Islamic State-held city northeast of Aleppo which Kurdish-led fighters are racing to take, and which lies close to the front lines of Assad’s allies.

Turkish-backed forces have made rapid gains since August, but largely through less heavily populated areas. Urban warfare around al-Bab is already taking a heavier toll. Five Turkish soldiers have been killed in the past week alone, three of them in a suspected Syrian government air strike.

“Right now the question is whether Russia will allow Turkey to seize al-Bab,” said the Muntasir Billah Brigade official.

“There’s a political equation here. It’s not about whether Turkey has enough tanks, soldiers and weapons, but whether there’s any room for such a move from Turkey in the equation.”