That sounds to me like a bunch of individual countries deciding to independently put boots on the ground. At that point what are they voting on as a group? (Though maybe that’s just what you’re suggesting should be done and I’m missing it)

I also wonder what good any sort of military/defensive pact is if any country can unilaterally decide when or when not to participate. It means you can’t depend on it and you may as well not have it then right? To be clear I am not saying military pacts are a good thing, but they do currently exist and participating counties can’t (at least shouldn’t) just pretend they aren’t part of one when it’s inconvenient.