Ukraine

I agree that Russia will not likely be defeated militarily (in the sense of 'fought to the point of literal material exhaustion'), but the Sovs were a very different beast than the modern Russian federation. Modern Russia doesn't have that capacity to spend - in manpower or in organization. If modern Russia had quarter of a million troops KIA in six weeks, not only would it utterly wreck their entire war effort, it would very likely sink the very future of their country.

I mean, they're doing a bang-up job of that as it is, but you know what I mean.