The west will change like Israel. It will become more right-wing if the left doesn't offer anything to combat terrorism. That's how the once-dominant Israeli left and left-centrists fell to near-extinction. They basically said the exact same things 20 years ago that our media and mainstream politicians are saying today. But voters need to feel safe and turned decisively right as a result of the left having no policies to counter terrorism.
Our police forces will militarize, the laws will change to give governments more authority to eavesdrop. We'll eventually pursue policies that are currently deemed politically incorrect, like Israel's security wall and programs like stop-and-frisk.