I couldn't be more of a pacifist, but the fact is that there is a conquering imperialist power with the stated intention of undoing the European experiment right next to us, and we can't afford to not have a military capable of guarding against that. That means we do need to spend money, work, and yes, emissions on that. It sucks, we could spend all that on much more positive goals.

And yes, if we are going to build hundreds to thousands of tanks, let's figure out how to build them together to one standard so that we don't have to support a logistics nightmare to keep that afloat. Or if we take R&D, what if we could come together and get the FCAS thing going, so we don't need to fly hundreds to thousands of jets, flying and fuelling a smaller number of more advanced planes instead.

And it is actually what you are saying, we have to operate on the assumption that Russia will park thousands of tanks on our borders and start rolling in. That means we will have to, and we will drop thousands of bombs on them. The question is, what will preparing for that cost in terms of for example emissions, and how many people will die until we can. If we don't prepare as if this is real in a decade, maybe sooner, then it will definitely be real.

If you want to argue this, go, be my guest, buy a ticket to Moscow, and try to tell Putin why this is going to be bad for all of us and the planet. I doubt you will be able to convince him.