On termination of an emergency in which officers and enlisted personnel of the national guard have been called or ordered into federal service by the president of the United States, in accordance with the laws of the United States, the officers and enlisted men shall continue to serve in the national guard until the dates upon which their commissions or enlistments entered into prior to the call or induction into the federal service would have expired if uninterrupted, unless discharged in accordance with federal or state directives.