And we often get ourselves into additional conflicts because of that intervention. We basically created Osama bin Laden by funding the Mujahideen (under bin Laden) against the USSR, where he gained a lot of notoriety and power. If we didn't get involved in a proxy war with the USSR by funding terrorist organizations, I think it's likely bin Laden wouldn't have gotten powerful enough to create al-Qaeda.

There are a bunch of other cases where our involvement has made things decidedly worse, to the point where a policy of non-intervention would probably have had a better net result.