I don't think most of them are that secret - also I'm not sure if they are aikido or ju jitsu techniques; but I'm sure we don't want to get into that argument!
Army combatives owe more to the influence of jujutsu and judo teachers than to aikido folks (Heckler et al included). However, the technique similarities are such that it doesn't much matter.
The Army FM covering combatives was originally, IIRC, written in the late 1930s or early 1940s and has been modified over the years since.
I hadn't seen a copy of it for several years and got my hands on a recent version earlier this month, as a matter of fact. Not a whole lot had really changed sine I last read it.
Nothing secret there, BTW.
And BESIDES, aikido IS jujutsu, anyhow, making it all pretty moot.
I think the underlying theme here is that 'if the military uses aikido, it must make aikido a pretty kick-ass martial art.'
If I missed the point, there, I apologize in advance.
Here's my take on the sunject.
It's not important. Really. Do you enjoy aikido? Does it offer something that enhances your life? Then aikido is the 'right' martial art for you.
If not, go find something that does. Combat effectiveness? Geez, go buy an axe handle or a handgun.
Budo (and yes, Virginia, aikido IS budo) is a great way to learn a lot about yourself, learn some _principles_ of unarmed/lightly-armed combat, leanr something about a unique and fascinating culture ...
It's NOT about being the best fighter on the block. Not today, anyhow.
cg aka LOEP