Do you really think it would be peaceful?
Lets go back to the Texas secession fantasy scenario again.
There are dozens of Federal military installations in Texas, both large and small, including two of the largest Army bases in the country (Ft. Hood and Ft. Bliss).
What are you going to do about them? Request that the 34,000 people at Ft Hood, most of whom are combat veterans, are NOT Texans, and extremely loyal to the USA just give up their base and equipment and "move along peacefully" because the "secessionists are in charge now"?
Yeah, that will happen, lol. It's about as likely as a Chuck Baldwin electoral landslide.
Even if that didn't start the ass whipping (with the secessionists being on the receiving end), all it would take would be a group of loyal US citizens who do not support secession asking for the military to help them- and the ass whipping would be on for sure.