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.
They're not really selling solutions if it still costs them at the end. For the most part, US foreign policy is a net negative for America's pockets and many of their "allies."
Digging a hole and covering it at a cost of $22 trillion will double America's GDP overnight. But it doesn't create value for anyone.
All it does is transfer money to the contractor doing the digging (in America's case, the military-industrial complex) while everyone else becomes poorer.
$8 trillion has been spent on the War on Terror so far. Like I said in another comment, that's enough money to build 80 million $100k homes, or reduce America's debt by 25%, or pay off all student loans, or build 400,000 KM of high-speed rail at $20M/km, or give every American taxpayer a one-time check of $48k, etc.
Every bomb dropped on Afghanistan or Iraq was money diverted from something else useful the US could have done.
