Last week, a company sized element of U.S. Marines operating out of the Tanf garrison in Syria kicked off a series of “show of force” drills intended to demonstrate in no uncertain terms the extent to which the U.S. military can respond if challenged in the region. A live fire aerial assault was conducted, demonstrating how quickly the Marines could respond to an approaching offensive force, and what level of destruction they promise to deliver — but the intended audience wasn’t Islamic extremists, nor was it even Bashar al Assad’s forces. The Americans were posturing with their eyes set squarely on Moscow, despite the canned nature of the sound bytes coming out of U.S. Central Command.

“Our forces will demonstrate the capability to deploy rapidly, assault a target with integrated air and ground forces, and conduct a rapid exfiltration anywhere in the OIR combined joint operations area,” Navy Capt. Bill Urban, spokesman for U.S. Central Command, told the media on Friday. “Exercises like this bolster our defeat-ISIS capabilities and ensure we are ready to respond to any threat to our forces.”

Despite the use of ISIS in official statements, these exercises did not come unprompted. Russian officials have issues warnings to U.S. personnel via the Syrian deconfliction line twice in the past week, saying they intend to initiate an offensive against the very region U.S. forces are currently occupying in support of Syrian Democratic Forces (SDF) at the garrison. U.S. troops not only operate out of the same installation as SDF force at Tanf, they also monitor and enforce a 34 mile (55 kilometer) exclusion zone around the base. The base is considered a key location for ongoing operations in the area, and as such, defenses are always on high alert. However, Russia announcing plans to engage in offensive operations within that exclusion zone insinuates plans to attack the base, or suggests that ISIS targets are operating freely within the area. The former could lead to war between the United States, and the latter seems extremely unlikely.

“The Russians informed the U.S. on Sept 1, via the deconfliction line, that they intended to enter the At Tanf deconfliction zone to pursue terrorists,” Central Command spokesman Army Lt. Col. Earl Brown said on Friday. “The Russians indicated via written note on Sept 6, that they would make precision strikes in the At Tanf deconfliction zone against terrorists. Coalition partners are in the At Tanf deconfliction zone for the fight to destroy ISIS. Any claim that the U.S. is harboring or assisting ISIS is grossly inaccurate.”