RT is too polite. US, Israel, and it's allies could not overthrow Assad. They could not defeat Russia's goal to save Syria.
"Islamic State (IS, formerly ISIS) was at the height of its power in Syria in September 2015, when the course of the Syrian war changed drastically. The Russian military put its weight behind the Syrian government to help drive the terrorist group out of the country. RT reports from Syria about Russia’s role in the conflict." - RT