Whether we stayed 10 months, 10 years, 20 years, 40 years, any amount of time you can name, upon our leaving the "scenario would remain the same".
So... aside from going there and doing some "cleaning" in the first place... why stay at all...?
Aside:
Many, many times on this forum I've explained why "victory" in any traditional sense of the word was impossible in both Iraq and Afghanistan. That's because in order to fight and achieve victory, one must first understand against whom one is fighting and speak that realization publicly. And we have yet to do that. I sense that "it's no longer in us".