Going back to the fear and hysterical behaviour - it really does a lot to shape our society, e.g. Trump capitalising on every terror attack for political gain, saying things which normally a majority of Americans would balk at. It is intentionally misleading, guiding a large portion public opinion through press, propaganda and fear, it's been done in America since the 70s see: Edward Bernays and involvement in Operation Condor partic Ecuador, Vietnam, Bill Clinton firing on Kuwait, Gulf War, Iraq War, continual drone strikes inflicting collateral damage in the name of stopping terrorism. Show me ANYTHING that indicates American foreign involvement has brought increased stability anywhere (edit: since World War 2). THERE IS NONE. It's as pointless and lacking in positive effects as the war on drugs.
Trump's isolationist stance, while horrible, in a way seems more more logical than continual foreign intervention. But, to look at the actual attacks recently - Omar Mateen was born in fucking Queens, the recent Nice perpetrator had no history of being religious, ate pork, drank, had a history of wife beating, becoming radicalised just prior to the attack. same pattern across most attacks, they are completely decentralised unlike the idea portrayed of a centralised plot and organisation behind 9/11 - and subsequent Iraq War, another huge US fuck up resulting in horrendous loss of civilian life. Anyway, point being, you can't start a war against a decentralised organisation or extremist manipulation of jihad to condone violent actions, preying on the unstable and disenfranchised.