Europeans on Sunday (8 December) welcomed the dramatic victory of rebel groups in the Syrian civil war, pointing to the weakness of his international backers Russia and Iran, but cautioned about what may follow.

Islamist rebels have taken control of key cities and declared they had ousted President Bashar al-Assad after seizing control of Damascus on Sunday (8 December), freeing prisoners held behind bars for years.

Assad reportedly flew to Damascus for an unknown destination earlier on Sunday, with his current whereabouts unknown.

The development ends his family’s decades of autocratic rule after more than 13 years of civil war that claimed the lives of more than half a million people.

The Sunni militant group Hayat Tahrir al-Sham said in a televised statement that Damascus had been “liberated, [and] the tyrant Bashar al-Assad has been toppled.”

The end of Assad’s dictatorship was “a positive and long-awaited development. It also shows the weakness of Assad’s backers, Russia and Iran,” the EU’s top diplomat, Kaja Kallas, said.

“Our priority is to ensure security in the region,” Kallas said, adding she was in “close contact” with regional ministers.

“The process of rebuilding Syria will be long and complicated, and all parties must be ready to engage constructively,” she added.

European Council President António Costa said that with the end of the regime, there “emerges a new opportunity for freedom and peace for all the Syrian people” that would be “crucial for the broader stability of the region.”

“The EU stands ready to work with the Syrian people for a better future,” Costa said.

European Commission President Ursula von der Leyen said, “Europe is ready to support safeguarding national unity and rebuilding a Syrian state that protects all minorities.”

“We are engaging with European and regional leaders and monitoring developments,” Von der Leyen said, adding the “historic change in the region offers opportunities but is not without risks.”

French President Emmanuel Macron said: “The barbaric state has fallen. At last. (…) France will remain committed to the security of all in the Middle East.”

The French foreign ministry also called on Syrians to “reject all forms of extremism”.

German Foreign Minister Annalena Baerbock called the fall of the regime “a great relief” for millions of Syrians but warned that the country must now not fall into the hands of “other radicals”.

Spanish Foreign Minister José Manuel Albares said on RTVE that he hoped there would be no “Balkanisation” of Syria, where different regions could end up being ruled by different radical splinter groups.

“We have to ensure that the Syrian people can decide how they are governed in the future and by whom,” Albares said. “And, of course, that the territorial integrity of Syria is preserved.”

Ireland’s Prime Minister Simon Harris said “the protection of civilians in Syria was “paramount” and urged a “peaceful transition as well as free and fair elections.”

“It is still too early to draw firm conclusions about what this will mean in the long run – both for Syria and the region,” Sweden’s Foreign Minister Maria Stenergard cautioned.

“It is now becoming important to have an orderly transition of power in Syria,” she said, adding that “protection of the civilian population, civilian infrastructure and unimpeded humanitarian access by international humanitarian law must be ensured.”

Lithuania’s Foreign Minister Gabrielius Landsbergis said the Syrian example would show Russia “can be kicked out and will go home”.

“The Baltics were right – the West is strong enough to win – we don’t need to fear “the Bear” in Ukraine or anywhere else he is causing chaos,” he added.

Russia, a staunch ally of Assad, whom it intervened to help in 2015 in its biggest Middle East incursion since the collapse of the Soviet Union, is likely to face a heavy blow to its standing in the Middle East that could force Moscow to shut down its Khmeimim Air Base around Latakia and the naval facility in Tartus.

The latter is Russia’s only Mediterranean repair and replenishment hub, and Moscow has used Syria as a staging post to fly its military contractors in and out of Africa.

Russia’s foreign ministry said in a statement its military bases in Syria had been put on a state of high alert but that there was no serious threat to them at the current time.

The statement added that Moscow was in contact with all Syrian opposition groups and urged all sides to refrain from violence.

[Edited by Owen Morgan]