Obviously, the people who don't want this to happen are people who have money invested in the ammunition companies, etc.  Marco Rubio is worried because he represents the Koch Bros and their money.  If I were the President, I would ignore every single one of these bastards.  Lindsay Graham, in my opinion, was always just a "fair weather friend" to the President. 

There's absolutely no reason to stay there or in Afghanistan either, for that matter.  If the USA couldn't get done in 17 years what they set out to do, I'd say it's kinda sorta a lost cause, wouldn't you?  This is about money (as usual) it's not about "national security".  We've been there long enough so that our gubmint certainly must have made a profit by now!!

https://www.politico.com/story/2018/12/19/trump-us-troops-in-syria-1068734

It will be done in steps, I'm sure.  I do, however, hope we don't lose the Kurds as an alliance.  They've been loyal, which is more than can be said for most of our allies.