I tried to read this whole thread but there are so many long posts. Still, most people are saying the same general thing so I'll go ahead and write a post that will be skipped as well.
To people saying "it's just a game", you already have completely missed one of Infinity Ward's goals in their entire career. They aren't just providing a game, they are trying to provide an experience. They really pushed this forward in Modern Warfare, putting you into the body of a man dying from a nuke shockwave, staring into a mushroom cloud in your final moments. Or from the very conclusion, where they don't have a boss fight but give you a choice few seconds to take aim and fire your shot.
Infinity Ward are masters of the video game equivalent of "directing". Where in film a director provides a shot composition that speaks as much as it shows, a game is focused on the experience. Thus anything Infinity Ward is trying to present isn't merely "hey, let's just make a fun shooter game". They are trying to provoke an emotional reaction, and because they are so good at it I will only buy CoD games made by them. Treyarch may do a decent job, but there's no way they will measure up to Infinity Ward.
That said, the major issue with MW2 is that the story was written around awesome things Infinity Ward wanted to include. MW1 was so carefully constructed and was plausible, but you know for MW2 they started the game saying "America is going to be invaded". The problem is making that happen. This level doesn't exist "to be controversial", it exists because they tried to make an excuse that could generate an emotional reaction from the player.
Unfortunately I also felt nothing, though I was uncomfortable with the fact that I felt no discomfort (if that makes sense). I still feel empathy when I see innocents and bystanders die on screen. I can pick out a select few movies that have deaths that always make my heart cringe. This game should have done the same thing, but it didn't. Maybe it's because the people are fake, but idealogically it should still be disturbing.
In any case, Infinity Ward tried to present a game where you had to see what it takes to bring a bad guy down. Sometimes you have to do evil for the greater good. They were hoping you'd feel bad about it and then shock you at the end of the level when you get shot. Ultimately it was an incredibly lame method of getting someone to invade America.
As for whether Russia is a likely candidate for war or not, let's backtrack to when America was finalizing some treaties with Poland for some missiles there. Russia was pretty adamantly against it and just about said "We cannot be held responsible for our own actions", basically saying "Yo, if America goes through with this we're gonna launch a nuke". Sure it was a bluff, but it happened and it showed that Russia is one of many likely candidates if you're going to use a fictional scenario.
When you consider others, the only ones are China, who we are tied with so economically the chances are nearly impossible, or North Korea, a militia way too small to conduct a full scale invasion of America. Then the rest of our "enemies" are even smaller than that.
Infinity Ward wanted to create a battlefield on American soil, and unfortunately that aspect was half-assed. However, the latter half of the story was technically not bad, where you discover your villain is actually the American General (and thus Britain remains the only good guys! Whee!). So in the end America and Russia look like assholes.
Still, the excuse "it's just a video game" is the sort of mentality that limits the medium as an art form. By being interactive games have so much more potential of generating an emotional reaction, but if you only look at them as "mere games" then how the Hell are the mainstream going to recognize them as anything more than toys for children?
