Part of US policy is to support factions in these regions that the US can control (which is in the nature of US self defense, these regions control critical resources).

To do that, we support individuals who would put US interests ahead of the interests of their own people (ie: they're traitors at the core). Furthermore, they must use methods that are strong enough and ruthless enough to halt advances of individuals in their own countries that would represent their countries interests (rather than the US's).

In short, we do it to ourselves, and we're not likely to stop anytime soon.