[learc83]

>some major chunk of the population

There's about 1.3 million active service members.

There are more than 200 million Americans of military age.

I wouldn't call that a major chunk.

Even if you look at the number of people who've served for any length of time at all, the number is very low. It's not a viable option for a significant portion of the population, because personel numbers are capped.