MOSCOW (AP) ― The Kremlin’s evacuation of Russians from Syria on Tuesday marks a turning point in its view of the civil war, representing increasing doubts about Bashar Assad’s hold on power and a sober understanding that it has to start rescue efforts before it becomes too late.

The operation has been relatively small-scale ― involving fewer than 100 people, mostly women and children ― but it marks the beginning of what could soon turn into a risky and challenging operation. Analysts warn that rescuing tens of thousands of Russians from the war-stricken country could quickly become daunting as the opposition makes new advances in the battle against the Syrian president.

“It’s a sign of distrust in Assad, who seems unlikely to hold on to power,” said Alexei Malashenko, a Middle East expert with the Carnegie Endowment’s Moscow office.

Russia has been Assad’s main ally, pooling together with China at the United Nations to block international sanctions against his regime. But it has increasingly distanced itself from the Syrian ruler, signaling it is resigned to the prospect of him losing power.

On Tuesday, four buses carrying about 80 Russians crossed into Lebanon, the first evacuation organized by Moscow since the start of the Syrian conflict nearly two years ago. Russia said a day earlier that about 100 of its citizens in Syria would be taken to Lebanon and flown home.

The land route was presumably chosen because of renewed fighting near the Damascus airport. One of two planes sent to pick up the Russians took off late Tuesday from Beirut for Moscow and the other was set to take off soon, the Emergencies Ministry said.

Malashenko said that the evacuation reflected a strong concern in Moscow that Assad’s fall would put Russians in grave danger. “There is a strong likelihood that Assad’s foes could unleash a massacre of those whom they see as his supporters,” he said.

In addition to tens of thousands of Russians permanently living in Syria, most of whom are Russian women married to Syrian men and their children, there are also an unspecified number of diplomats and military advisers along with their families. The evacuees were permanent residents not connected to the embassy.

In Washington, State Department spokeswoman Victoria Nuland said the news of Russians leaving Syria “is not surprising and it speaks to the continued deterioration of the security situation and the violence that Assad is leading against his own people.”

Asked about the government’s faith in Assad, Nuland added: “If you look at the Russian public statements over the last month, they have been evolving somewhat in terms of the level of confidence in whether Assad was going to make it or whether Russia actually had an interest in that.”

Georgy Mirsky, the top Middle East expert with the Institute for World Economy and International Relations, a government-funded think tank, warned that Russians in Syria are facing growing risks.

“Many are reluctant to leave, hoping that the situation could somehow stabilize,” he said. “But Aleppo is already half-ruined, and it will soon come to that in Damascus too. Sooner or later, Assad is going to lose.”

Russia could rely on Assad to provide a military escort for caravans of refugees, but such protection may not be reliable enough with the Syrian army’s resources drained by the need to battle rebels all around the country.

Refugee convoys could make an easy target for the rebels when they try to move to neighboring Lebanon for a flight home. Direct Russian flights to Syrian airfields also would be a risky option with rebels possessing portable anti-aircraft missiles.

“That’s why they sent the planes now without waiting until the 11th hour when rebels come close to victory,” Mirsky said.

Alexander Golts, an independent Moscow-based military analyst, said that if Russia sees Assad’s defeat as imminent, it would have to quickly organize a massive air bridge to take its citizens home.

He said that such an effort would be extremely challenging and require sending troops to protect an air base in Syria that would be chosen for the evacuation to make sure that no rebels armed with anti-aircraft weapons are in close vicinity.

Even now, with Assad’s forces in control of the area around Damascus, Russian planes flew to Beirut in a clear move to reduce security risks, Golts said.

A Russian navy squadron, currently in the Mediterranean, is scheduled to conduct maneuvers off Syria’s shores later this month. It includes four landing ships capable of carrying several hundred marines and armored vehicles.

Golts said that that the marines on board the vessels could be deployed to protect an airfield in Syria if Moscow decides to launch a massive evacuation effort.

“Under the most favorable circumstances, it will be barely enough to take control of an air base and ensure its relative security,” Golts said. Protecting the area around the base chosen for evacuation is essential to reduce risks posed by portable anti-aircraft missiles, which rebels already have used to down Syrian military aircraft.

The Russian government has given no signal that such an operation could be in the making.

Russian officials have said that both planes and navy ships could be involved in the evacuation of Russian citizens. Russia has a navy base in the Syrian port of Tartus, the only such outpost outside the former Soviet Union, which could be used for loading the evacuees on sea vessels.

Officials haven’t given any indication yet that the landing vessels now in the Mediterranean could take any evacuees on board. And after the ships head home after the maneuvers, it would take weeks for another squadron to reach the Mediterranean.

A mass evacuation of Russians from Syria would face other logistical challenges.

The Russian Foreign Ministry has said that it has contingency plans to evacuate Russians, but it has admitted that only a few thousand of tens of thousands of Russians have left their contact details at the Russian consulate.

Golts said that if the escalating fighting forces Russians to flee Syria en masse, they will have to get to the planes themselves through the war-torn country. “It’s hard to imagine how they could organize military protection for convoys,” he said.