> It makes no sense from a military perspective.

Given that the reason is political pussyfooting that can be very true while offering no explanatory power for the question at hand.

I could understand holding back while the things where still on a jittery scale at the start of the conflict (don't want your gear picked up by the other side the the day after it arrives).

But since the Ukrainians started pushing them back, I have very little respect or patience for the tempo of the material help they have been given.

They have been trying to boil the mythical nuclear frog without making it jump out of the pot. And as long is it is only Ukrainians dying, a slower boil is of course the safer choice...