After multiple incidents in which US planes have attacked pro-government forces in southern Syria, the Pentagon has now deployed long-range rocket artillery to the area near the rebel base at al-Tanf, raising concerns the US is going to escalate attacks against pro-government forces near the Iraqi border.
This is the first time the US has deployed rocket artillery in the area, and adds to an ever growing footprint of US troops and equipment deployed at al-Tanf, which was supposed to be a base for moderate rebels resisting ISIS, but which is increasingly focused on limiting government expansion into ISIS territory in the area.
Officially, the US has presented its attack on pro-government militias as “self-defense,” arguing that they believed the militias were too close to Tanf for their comfort. The Syrian government has noted the US was never authorized to send ground troops into Syria in the first place, and heavily criticized their attacks on pro-government forces as intended primarily to prevent ISIS losing ground to them.
Though the US clearly has no preference for ISIS either, they are heavily backing an invasion of ISIS territory by the Kurdish YPG, and may be hoping to leave more of the ISIS scraps in the oil-rich east for the Kurds to seize, rather than allowing them to return to government control
To make matters even riskier, the artillery systems in question have an operation range in the hundreds of kilometers, meaning that they are not only able to target Syrian forces close to Tanf, but potentially the ability to hit most anywhere within Syria at will.