It often flies under the radar – until it flies into the Russian GRU's face – but the U.S. military presence in Syria is a constant aggravation for Russian President Vladimir Putin's government.

Russia's particular gripe is the ongoing presence of U.S. forces in north and eastern Syria. While those forces are primarily deployed to fight the Islamic State, they also help deter Turkish attacks on Kurdish settlements, and Syrian-Russian-Iranian attacks on Sunni fighters/residents east of the Euphrates river valley. Vladimir Putin knows that until the U.S. removes its forces from Syria, he'll be unable to ensure that Bashar Assad's government dominates all other Syrian actors. In addition, Putin won't be able to use his leverage over Iran in order to win concessions from the Saudis and Israel.

Iran wants to use Syria to establish a contiguous land corridor from Tehran to southern Lebanon, but America's presence is an obstruction.

Russia intends to force the U.S. out. Originally, Putin attempted to persuade President Trump to withdraw U.S. forces of his own volition. But that didn't work because Trump rightly took the advice of his advisers. Trump has committed to staying until ISIS is finally defeated and Assad accepts a realistic political transition process. Since then, in true KGB form, Putin has tried a mixture of threats and manipulation.

The Russian military has repeatedly threatened attacks on U.S. forces and against civilians in areas like Idlib governate. But Putin has also promoted an absurd diplomatic process known as the Astana track. This track is outside of the U.S. and Syrian rebel-supported Geneva framework, and exists simply to give Assad cover to end the Syrian civil war on his terms. Unsurprisingly, the U.S. has rejected Astana for the lie that it is.

But now the Kremlin is freaking out again. Last Friday, the Russian foreign ministry spokeswoman decried that "the U.S., which had observer status at the Astana format, abstained from sending its representative to the 11th international meeting of high-level representatives on Syria. It appears that our U.S. partners have their own plans for Syria, and they show little concern for efforts to achieve a political peace settlement in that country."

Although utterly absurd, this Russian agitation reflects a disappointment that the U.S. has been unwilling to recognize Russian hegemony in Syria. But that wasn't the spokeswoman's only gripe. She added that when it comes to "U.S. actions on the eastern bank of the Euphrates River... it is impossible to say that these actions conform to international law."

Yes, there is defining hypocrisy in Putin's government referencing international law. Still, the Russian warnings here do reflect the likelihood of near-term escalation against the U.S. in Syria. This is an especially important concern in light of Trump's rebuke of Putin at the G-20 summit last weekend. Putin, put simply, does not like to be embarrassed.

One way or another, get ready for new Russia escalation in Syria.