Modern weaponry and strike capacity is pretty effective when it comes to rapid, hard hitting strikes. Give me a squadron of B-1 or B-52 Bombers and I'll level a city in ten minutes. I'm not saying the plot's perfect, but then again what plot isn't? As for them advancing so quickly, the entirety of Europe was pre-occupied dealing the thousands of dead civilians from the gas attack. Bearing in mind the target of that attack was key C3 and Intelligence centres. The Russians had effectively blinded Europe, combine this with fast moving attacks by armoured and airborne attacks by Russian units stationed in Eastern European states (which in the MW cannon are once again part of Russia). Much like MW 2 with its retarded satellite module being the Achilles heel of the US early warning network, the plots not full proof, but neither is it completely implausible. This is a fiction shooter, not a military simulator. Certain things are done for dramatic effect, which don't really make too much military sense on the face of things.