I love how the latter part of this thread devolved into "X vs Russia" let alone military technology, tactics and history.
I hate to chime in given all these informed tactical savants forecasting the results of a US vs Russia war, but I feel obligated to point something out..
Should Russia and the US collide in conventional war, and the rest of the world not intervene to diffuse the situation in time, we would literally see MAD doctrine come into play. That fact alone IS the single most powerful deterrent in terms of preventing a US vs Russia war.
On the note of ICBM's which I read in the earlier part of this thread.. that gave me a pretty good laugh.
The US military has had the ability to eliminate ICBM's for a few decades now. Those methods of ICBM elimination have multiplied over time, and now the US military is actively (and successfully) testing technology to eliminate ICBM's that equates to science fiction made reality. However, should Russia launch ICBM's at the US the fact of the matter is there will be far more ICBM's in flight then there are US countermeasures available.