If you're a young guy in high school or college, or just starting out your career, go to the websites for Lockheed Martin, Raytheon, Boeing, and whatever other defense contractors you can think of.
Look at their "Early Career" job listings (they'll have pages specifically for this). You might be surprised as to what you qualify for, or will qualify for right out of school. They really do everything, and love hiring new grads.
They will pay for you to get your Secret (and sometimes Top Secret) security clearance, which you retain after leaving the job. Once you're "in" the boy's club that is the defense industry, you're part of the club for as long as you want. It's easy to hop jobs and even firms. Most people don't leave unless it's for an MBA to hop into something like Finance or Consulting.
As long as America's an empire and you need a job, you might as well be a part of what keeps the gravy train rolling.