The President is both the head of state and head of government of the United States of America, and Commander-in-Chief of the armed forces. Under Article II of the Constitution, the President is responsible for the execution and enforcement of the laws created by Congress.
You can join some branches of the United States military at the age of 38 years but not others. The Army, Navy, Air Force, Marine Corps and Coast Guard each has its own minimum and maximum age requirements for enlistees, including for new recruits in the active-duty ranks, the Reserves and the National Guard.
Under federal law, the minimum age for enlistment in the United States military is 17 (with parental consent) and 18 (without parental consent). The maximum age is 35. However, Department of Defense policy allows the individual services to specify the maximum age of enlistment based upon their own unique requirements. 1  The Air Force tends to have an older upper limit for enlistment, whereas the Marine Corps' cutoff age is younger than the other branches of the service.