In the military though aren't people enlisted for specific amounts of time, so if the military no longer wanted them around it could just not allow them to reen

In the military though aren't people enlisted for specific amounts of time, so if the military no longer wanted them around it could just not allow them to reenlist when their current term expires? Even if you have a lot of time left on your current enlistment period and they don't have cause to toss you out, couldn't they reassign you for the rest of your term to something else?