The US said on Wednesday it was sending F-22 fighter jets to Syria to counter threats from Russia, underlining how a military mission that started with the aim of combating the Islamic State militant (IS) group has turned into a wider geopolitical scramble.
As the Syrian conflict has progressed, Washington's rivals, Iran and Russia, have entrenched themselves in Syria - at a time when Bashar al-Assad is regaining friends in the region.
US troops arrived in northeast Syria in 2015 as part of Operation Inherent Resolve. Working alongside the Syrian Democratic Forces (SDF), a Kurdish-majority militia, they pushed back IS after it swept through vast swathes of Syria and neighbouring Iraq. The so-called "caliphate" was territorially defeated in 2019.
Militarily, the US mission continues to be a success.
During Ramadan this year, IS managed just 19 attacks in Syria, a 37 percent decrease from the same period last year and 70 percent less compared to 2020, according to the US-led coalition.