Recent attacks in Istanbul and Berlin remind us that preventing violent extremism must be a policy priority for the incoming Donald Trump administration. The last decade has shown that our good intelligence will never prevent every terrorist attack, and our aggressive reactions will never kill or scare away every potential terrorist. But we can do a better job of stopping the terrorist plots in the first place. The way to do this is to get communities that produce and harbor attackers to view America and the West more favorably. Targeting terrorist groups overseas is not enough. Tools of terror are everywhere. From the readily available explosive components to the semi-automatic weapons that can be purchased everywhere (including online) to the vehicles we drive every day, a would-be attacker has an almost infinite set of options. We need to intervene early, and the only way law enforcement can do that is with the cooperation of the communities within which potential terrorists live.