Which countries were involved in the war and why?

A dramatic advance by Syrian rebels ended the decades-long rule of Bashar al-Assad, when opposition forces seized the capital and forced the president to flee on 8 December.

Its overthrow followed a 13-year civil war, which began after Assad crushed pro-democracy protests, killing more than half a million people and displacing millions more, including international powers and their embassies.

The world is now watching to see what the political situation in Syria looks like after the century-long overthrow of the Assad family.

Those who have a strong interest in this conflict and the future of the country include, on the one hand, Russia and Iran – which supported Assad – and on the other, the US and Turkey, which support different rebel groups.

Here we examine how those countries, along with Israel, have played a role in Syria – and may continue to do so.

During the civil war in Syria, Turkey has supported the opposition forces – especially the Syrian National Army (SNA) – by providing weapons, both militarily and politically.

Syria’s neighbor to the north was more concerned he is using the rebels to contain the Kurdish YPG militiaTurkey accuses it of being an extension of the outlawed Kurdish rebel group at home. Turkey also wants about three million Syrian refugees living in its country to return home.

The YPG is the largest force in another rebel group, the US-backed and Kurdish-led Syrian Democratic Forces (SDF) coalition.

During the war, the Turkish army and the rebels joined forces he seized many places from these groups along the northern border of Syria.

Turkey is also involved in politics. In 2020, Turkey and Russia made a truce to stop the government’s push to retake Idlib, a rebel stronghold in the northwest.

Idlib has been under control since 2017 under the so-called government the Islamic terrorist group Hayat Tahrir al-Sham (HTS), which led to the rebels who eventually overthrew Assad.

Many believe the invasion could not have taken place without the blessing of Turkey. Turkey has denied supporting HTS.

Meanwhile, conflicts in northern Syria continue: As Assad falls, the SNA launches separate attacks on SDF-held areas.

Russia already had a decades-long relationship with the Assad government, and had military bases there before the civil war.

In 2015, Russia launched an air campaign and sent thousands of troops to support the Assad regime.

In returnRussia received 49-year leases on the air base and naval base, which provide key points in the eastern Mediterranean for transferring military contractors in and out of Africa.

But fighting a war in Ukraine since 2022 worried Assad, which contributed to the Syrian army’s defeat of rebel groups in late November and early December.

Assad and his family have found refuge in Moscow after fleeing Damascus, Russian media reported.

After the pro-democracy protests in Syria in 2011 were met with force, then US president Barack Obama criticized the Assad government – but only the US. he got involved in the military to fight the Islamic State (IS).

The US-led coalition has carried out airstrikes and deployed special forces since 2014 to help the Kurdish-led SDF rebels retake territory previously held by IS militants in the northeast.

After the fall of the Assad government, the US government it said and did a series of airstrikes against IS camps and personnel in central Syria to ensure that IS cannot take advantage of the unstable situation.

However, President-elect Donald Trump, who takes office in January, he said syria is “chaos” the US should stay out. When Trump became president in 2019, he withdrew US troops from Syria, which his officials gradually backed away from.

The US currently has approximately 900 troops in Syria.

Iran and Syria they were partners since Iran Islamic Revolution in 1979. Syria he supported Iran during the Iran-Iraq war in the 1980s.

During the Syrian civil war, Iran is believed to have deployed hundreds of troops and spent billions of dollars to support Assad.

Thousands of Shia Muslim fighters armed, trained and supported by Iran – most of them from the Lebanese organization Hezbollah, but also from Iraq, Afghanistan and Yemen – are also holding the Syrian army.

But like Russia, Hezbollah has been weakened by the conflict with Israel in Lebanon, which may have hastened the fall of the Syrian army.

Israel shares a border with Syria. In the 1967 Six-Day War, Israel captured the Golan Heights, about 60 kilometers (40 miles) south of Damascus, from Syria, before retaking it in 1981.

Israel do air strikes against Iran-linked targets in Syria during the war, although it rarely agrees to such strikes.

Since the rebels overthrew Assad, Israel has make hundreds of attacks on the other side of Syria. Targets include Syrian military infrastructure, warships, and weapons production facilities.

Israel said it was trying to stop weapons falling into the “hands of extremists”.

The Israeli army had them too seized an unauthorized buffer zone Golan Heights and may have diverted to nearby Syria.

BBC Verify has obtained a photo of an IDF soldier standing a little more than half a kilometer beyond the protected area, inside Syria on a hill near the village of Kwdana.