I've no idea about the military but when I go travelling to places where sanitation isn't great I pack two things; firstly, a portable water filter (I hear that Innova is good
http://www.innovapurewater.com/html/products/products_intro.htm also
http://www.indoorclimbing.com/Portable_Water_Filter.html) and activated charcoal tablets which work a charm if you do happen to get stomach trouble (I use Ultracarbon tablets
http://www.merck.co.th/en/pharma/products_otc_ultra.asp but other medical grade activated charcoal tablets should work). Uh and... believe it or not, condoms are handy as a water container, they're small and light and they carry about 1 litre of water, very important in the desert if your canteen is broken or cracked, just as a precaution. A magnifying glass works as a light-weight, non-consumable fire-starter, might be useful to have on hand in an emergency, especially in the desert. Also, it's handy to get a small water-proof LED torch light, LED torches last significantly longer than iridescent torches and are therefore more reliable in many situations.
Also, I know from experience that a deck of cards provides much entertainment and doesn't require recharging every few hours.

Even though I'm no vet, I hope this helps.
