Funny thing about American meddling is that it always comes back to bite the US in the ass. The War of Terror has cost $8 trillion and there's nothing tangible and lasting the US has to show for it. Groups like Al Qaeda, ISIS (esp. their networks across Libya, Iraq, etc.) are offshoots of American meddling in the region, growing healthily despite everything.
Afghanistan, Vietnam, Iran (now a rabid enemy), Iraq, Syria, and Libya, are all failures of that World Police ethos that the US refuses to disengage from.
Afghanistan, Vietnam, Iran (now a rabid enemy), Iraq, Syria, and Libya, are all failures of that World Police ethos that the US refuses to disengage from.