Sid is love!

[Come for the snark, stay for the deeply-obsessive canon...]

Huh. I never thought about that. We really only see him in uniform in the Washington ep [my brain for episode titles is apparently out doing research...][It's "Secrets". *DUH*]

My first guess would be that Jacob was Support Track rather than Combat Track [you specialize in one or the other fairly early in your military career, and it's Conventional Wisdom that Combat Track gets the best promotions; for example, both Jack and Hammond are Combat Track officers]; but there isn't much canon on Jacob. I don't think anybody's ever done a takedown on his fruit salad, either.

But I get the impression from the fb in which Sam thinks about her mother's death [I think that's "Netu, Part 2, where Jack drinks something that reminds him of the Seventies"][okay, it's "The Devil You Know", because I can't live without checking], it's clear that Jake is Stateside at the time, which [in my mind] lends weight to him being on the Support Side. That, and the fact he's clearly in his native habitat at the Pentagon [which must have been such a joy for Sam while she was stationed there...]