Foreign involvement in the Syrian civil war

Most factions fighting in the Syrian civil war received various types of support from foreign countries, groups, and entities based outside of Syria. As a result of extensive foreign intervention, the war in Syria was widely considered to be a series of overlapping proxy conflicts between both regional and global powers, including between Russia and the United States, Iran and Saudi Arabia, Iran and Israel, and Israel and Turkey, among other geopolitical struggles.

Source: Wikipedia — Foreign involvement in the Syrian civil war (CC BY-SA 4.0)