The idea that the United States has not intervened in Syria and is guilty of “inaction,” is a myth however. The United States and its Western and Gulf Allies have intervened in the Syrian conflict from early on. US planners have been fighting what the New York Times described as a “$1 Billion Secret C.I.A. War in Syria” while providing weapons to rebels through a program considered “one of the costliest covert action programs in the history of the C.I.A.”
https://libertarianinstitute.org/the-myth-of-us-inaction-in-syria/