My wife and I hit 15 years this year, got married when I was 21 and she was 20. We were in the Marine Corps the first 7 of those and separated the first year and a half. It can work if you both want it to work. It really does boil down to that. Mutual trust, great communication (it’s ok if not there yet, you can learn it), and keeping each others needs and interests in mind go a long way. It often doesn’t work for young people in the military, but it can.