The Syrian regime and Iranian militias have increasingly tried to encroach on U.S. allied territory, leading to warnings and occasional bombings. Iran is particularly concerned with U.S. influence inside Syria, despite American insistence that its presence in Syria is focused on defeating ISIS. Russia is also the main ally of the Syrian regime and has significant military assets inside the country.
"The chance for a catastrophic error is higher now than ever before in the six-year-old civil war," U.S.-based intelligence advisory firm The Soufan Group noted Tuesday.
U.S. anti-ISIS strategy in Syria relies on the Syrian Democratic Forces (SDF), a group largely composed of Kurdish fighters. The SDF are supported by U.S. airpower, and they have begun their assault on Raqqa. Iran and Syria, however, are trying to probe the SDF’s territory, which include U.S. troop advisors, in the hopes of capturing the territory for themselves.
This hope has led to numerous armed confrontations between the U.S., Iran, and Syria. The U.S. shot down an Iranian made armed drone over Syria Tuesday, just two days after it shot down a Syrian regime fighter aircraft. The U.S. also shot down an Iranian made drone over Syria on June 8. These aerial engagements are unprecedented in recent years
The June 8 shoot-down of an Iranian drone over Syria was the first U.S. air-to-air engagement since February 2009. The Syrian shoot-down was the first U.S. air-to-air kill since 1999. Compounding the problem, Russia pledged to treat all U.S. aircraft in Syria west of the Euphrates river as "targets" that would be tracked by their aerial defense systems deployed inside the country.
The Pentagon vowed to continue all its anti-ISIS operations in Syria after Russia’s warning.
"The Coalition does not seek to fight Syrian regime, Russian, or pro-regime forces partnered with them, but will not hesitate to defend Coalition or partner forces from any threat," CENTCOM declared in a Tuesday statement.
"Iran is nervous about what the Americans are up to in Syria ... They want to go after the American sphere of influence" Middle East expert Hassan Hassan told Al-Monitor. Their message for the U.S. is "we can make things messy for you in Iraq and Syria," he declared.