I'm not saying what I
want to happen, I'm saying what I
expect to happen, given the hypothetical circumstances.
The 'leadership' will be the military command, who will deal heavy punishment on Islamic states. On the ground in the USA, individuals on their own initiative will initiate a cleansing campaign here at home, and the authorities will be loath at best to stop them.
In 1957, President Eisenhower deployed the 101st Airborne to Little Rock to enforce a federal desgregation order at Little Rock Central High School.
The 101st Airborne followed orders, even though they were deployed against US citizens. I think we can expect the same pattern in the future.