My older son joined the Marine Corps 9 months after 9/11, when he turned 18.
:) my son was 9. He wanted to donate blood, send water to the guys at ground zero, and join the Army, then the Air Force after they brought simulators to town and he aced the mission (I was flying around in circles), but I told him if he went he would get the best training in the Corps. It was one of the few times he took my advice. Better to give strong willed children multiple choices.
Give yours a hug for me.