What is CBA?
CBA = Cross Border Authority
Without orders from POTUS the military can do many, many things; move airplanes and men from super far away to a standby status immediately outside the country in which the final national action is to take place (or not).
They can do MANY things without orders from POTUS but they absolutely CANNOT cross a national border w/o permission from the President.
Actions at the national level require orders from the national level, i.e., POTUS.
NO ONE but POTUS can give that authority.