Latin Motto

[golgotha]

I'm wondering about the provenance of the Special Forces motto, "De Oppresso Liber." I've gathered that the official Army translation is "to free the oppressed." I've studied Latin for years, though, and it pretty clearly doesn't say that. The Latin for that would be "Oppressos Liberare" or similar. The current motto is kind of odd Latin, and the meaning isn't immediately apparent, but it could be translated as "From an oppressed [place/thing/person] -- free."

I searched this site, and found a post from Airbornelawyer, who seems to agree that there's a big difference between the Latin and the official translation.

So, I'm interested to know how, why, and by whom this Latin phrase was chosen as the SF motto. What's the story behind it? I've searched this site and the web generally, and read into some SF history, but couldn't find any pertinent info. Anyone know?