This is simply not true. Treason is charged by CONgress and prosecuted by the DOJ. There are also state treason charges, and yes - the military can bring treason charges on military members and DOD employees.
If the Federal Court system can be shown to be non-functional it is possible for the President to establish military tribunals and only then could they prosecute Treason against civilians.
Well if "the military is the only way" then that implies republicans still wont do jack shit to arrest anyone.
The military is in charge of Treason cases
This is simply not true. Treason is charged by CONgress and prosecuted by the DOJ. There are also state treason charges, and yes - the military can bring treason charges on military members and DOD employees.
If the Federal Court system can be shown to be non-functional it is possible for the President to establish military tribunals and only then could they prosecute Treason against civilians.