I've never been in the military (Geneva Conventions prohibit these hands), so I have nothing to base this on, but I suspect a lot of these marriages are formed in order to gain the substantial spousal/family benefits paid out by the military. So my point is that many of them may simply just be marriages for profit rather than actual love, and if that's the case, well...
At one point I was seriously considering Air Force OTS, but I had a gf at the time whom I actually loved, so I passed. I always thought the only way I'd ever enlist was if I didn't have any attachments; the idea of getting married before you deploy was bizarre to me. Then I became aware of the spouse/family benefits