He honestly wouldn’t need to.

In a past life I worked with a LOT of senior military folk for the purpose of grants and funding and the like. And basically anyone (guesstimating) above the rank of a Captain equivalent (outside of SF) is basically a lifer. And they very rapidly learn how political the upper echelons are and that they need to stay as neutral as possible to get further promotions and have good assignments.

I could very much see various Lieutenants and even some Captains complain about leaving the Ukrainians to die. They will then be immediately told by the nearest Major or General that they are a disgrace to the uniform for refusing orders and blah blah blah. And that will propagate down the line so that the NCO who is ACTUALLY valued for their initiative understands that they will be brought up on treason if they violate these orders.

Because those Generals? They build their entire lives around always being able to say “I was just following orders”. They KNOW when you get things in writing.