Is Army War College currently an "absolute" discriminator for promotion to O-6 as a USAR JAG Officer?

I don't believe it's "absolute" for JAG. I base this on knowing several basic branch officers who made O6 without it. I cannot believe that a specialist branch would be more strict on a MIL ED "requirement" that the basic branches.

Note: I 100% believe that it is an important selective criteria. Just not absolute.

LTC (Join to see), I can't speak specifically to the Judge Advocate General's Corps, but in the mid-nineties, I worked for an O-6, then attending the USAWC via the DEP. He stated then that the greatest single cause of attrition in the program was O-5s being picked up for O-6! So, at least at that time, completion of the USAWC was not an absolute criteria for selection to O-6.
I do agree with COL Vincent Stoneking, that completion of the school is an important selection criteria.
BTW, the O-6 of whom I spoke later made O-8, so perhaps some of those O-5 dropouts short changed themselves!

A lot of check the block "must haves" for line officers aren't necessarily required for specialty branches (AMEDD, JAG, Chaplains, etc). However, if you DO complete War College, it does tend to separate you from your peers, and definitely gives you a nice check in the plus column.....