“Guarding the oil” was never supposed to be a part of the U.S. mission in Syria, period. Jim Jeffrey and the military leadership explained it to Trump as “let’s keep Syria’s oil” because they knew it would be the easiest way to sell an otherwise geopolitically useless deployment. https://twitter.com/katiebowill/status/1358870431952961540

As usual in these kinds of operations, a strict counter-ISIS mission turned quickly into a U.S. training and assist mission on the ground, which eventually included U.S. ground forces going on useless patrols in the northeast. CT turns into a quasi-stabilization campaign.

Over time, U.S. mission in Syria transitioned from countering ISIS to countering ISIS, Assad, Iran & Russia simultaneously. DoD can talk about the need to keep ISIS down all it wants. But the original mission has been subsumed—and we’ve had little debate about it.