They so want Trump to make the first move so that they can remove him from office.
If a preemptive attack turns out to be successful, they will do their best to give credits to McMaster rather than Trump, but if the ensuing aftermath gets messy, somehow they will change their mind and pin the blame on Trump again.
Correct, and that's also the reason Mueller is begging to be fired.
"Never do what your enemy wishes, for this reason alone, that he desires it" - Napoleon.