In 1920, the Supreme Court applied the Supremacy Clause to international treaties, holding in the case of Missouri v. Holland, 252 U.S. 416, that the Federal government's ability to make treaties is supreme over any state concerns that such treaties might abrogate states' rights arising under the Tenth Amendment.
Age. To join the Military, you have to be at least 18 years old (17 with parental consent). As for the upper age limit, it depends on the Service and the program: Health Professions Scholarship Program (HPSP): 36 (for the Navy, you can be no older than 42 at the time you enter Active Duty, following your degree completionâunless you were granted an age waiver when you were recruited)
Marines. To enlist in the United States Marine Corps, applicants must be between the ages of 17 and 29 prior to joining. Applicants to the Marine Corps Reserves must meet similar age requirements.Applicants who have complete previous service may re-enlist up to the age of 32.pplicants enlisting to become an officer must be at least 19 years old and no older than 35 years old. To qualify for the Navy Reserve, applicants must be between 18 and 39 years of age. Age restrictions may be waited for positions in high demand.