You can start to Network now.
Get on USAjobs.com and start looking at the jobs that they have posted. Get an idea of what certs to get because these jobs will post that info. Other sites do this as well.
The Govt like to use the GIAC certs. So checking out SANS university (not a college) and try saving some money now to attend those courses and then get the cert at the end of the class.
Being in Afgan should give you some time to study. Study read up on books. Have ur wife send you a cheap laptop she bought off craigslist for you and then use that to hack into and practice so when you get out you can be well preprared.
Job market is tough right now. So you need to make yourself look better than me. How are you going to do that? Figure it out. Send out random emails to companies seeing if they can offer you advice on how to get into the field and what they would do or what they did to get into the field. I've done all of this stuff as well as taking classes at SANS & InfoSec (and still no job)
Keep ur head up. You and I will both get a job in the fields we love with some hard work.
Security+, Network+, C|EH, CHFI, CPT