Extremists and terrorists are testing the limits of conflict in the Middle East and in Europe. More than the limits of conflict, they are testing the limits collusion. Conflict or collusion, or both, there is little that the U.S. can do and even less, that it should do. Collusion and conflict, is the business of the extremists and terrorists from all sides and so, it is for them to resolve. Joe Biden is waiting for this to happen.