Iraq, afghanistan, syria, libya, gulf, VIETNAM... the list continues
syria used to be a really nice place. Yes there were some terrorists, but remember that the USA created those terrorists. That's right. In the Soviet-Afghan War, the USA wanted to kick the Soviets out, so they employed all these mujahidin, etc.
those mujahidin were later angry that USA didn't pay them and wanted to take revenge.
The USA didn't pay their mercenaries. that's why those mercenaries are called terrorists now.