Don't know if any of this has been posted before, but
MREinfo.com has a bunch of good detailed information on US military rations and the sort of major NATO players (UK, Germany, etc) and some minor ones.
They also have a discussion forum for collectors which has information on rations from all over, including some T2K noteworthies:
A very good write up on the East German Army's field rations, with photos of packed (and opened) contents.
Polish MRE Equivalents (I think anachronistic for 1990s timeline, but who'd really know? -- And for the truly hard core gaming group, I think the thread has links to a site you can order from . . .)
Russian IRPs (MRE Equivalent) menu translations -- again anachronistic, but if I remember right there's a website that mostly does WW2 reproduction rations for reenactors that does a repro of the Afghan War-era Soviet Mountain Ration.
And various other threads covering a lot of detail on popular MRE equivalents, as well as some details about many smaller nation's rations.