The U.S. needs to increase its ability to engage in covert warfare against Islamic terror supporting states. It's not necessary or practical to invade, conquer and occupy every state that undertakes hostilities toward the U.S. or supports Islamic terrorism. We already have major military commitments that will probably continue for the foreseeable future. Launching a large military operation, particularly a preventative or preemptive war, is a serious diplomatic and political problem. After the experience of the Iraq War, the public is highly skeptical about such ventures, and there is likely to be massive international opposition to any such efforts.
But countries which are openly hostile to the U.S., help kill our soldiers, interfere with our operations, and undermine our allies should not be allowed to act with impunity, just because we aren't in a position to go to war against them. There are other ways to make them pay a severe price for their actions, and I'm not talking about largely useless economic sanctions. Along with the assassins, we should establish teams of saboteurs, which the CIA could recruit from people with the necessary skills, such as ex-special forces operators and members of private military corporations.
If we aren't in a position to respond overtly to hostile acts, these saboteurs could exact retribution covertly by destroying or damaging military targets and vital infrastructure. Direct hostility toward the U.S. might be less attractive when bombs start exploding in your military barracks, power plants mysterious shut down, bridges collapse, border posts are destroyed, mines start appearing on military routes, and so forth. I hope we are already doing some of this, but if so, it's one of our few well-guarded secrets.