Say I own a spoon company. The government says "hey, I'd like to buy a million spoons from you!" I say "sure, sounds great." We sign a contract stating that I'll give them 1M spoons and they'll send me $1M.

Then the government comes to me and says "hey, actually, turns out we need 500,000 forks and 300,000 knives and only 200,000 spoons."

I say "no, we are a spoon company. Very passionate about spoons. Producing forks and knives would be an entirely different business, and our contract was for spoons."

The military now threatens to destroy my company unless I give them forks and knives instead of spoons.

You say "the voters and congress tell the military how to use utensils, not SpoonCo. Shifting the decision to SpoonCo takes power away from the citizenship."

The military can sign contracts if they wish! They can decline to sign contracts if they wish!

But private citizens can also choose whether to sign or not sign contracts with the military. Threatening to destroy their business if they don't sign contracts the military likes (or to renegotiate existing contracts in the military's favor) is a huge violation.