I'm probably one of the few people who never got to play Modern Warfare 2, but I did play Call of Duty 4: Modern Warfare. Now I bought MW3, but I'm worried I might be a little lost on the story. So I'd just like to know the basics of the MW2 plot before diving into MW3, no extensive answer necessary.
Assuming I remember the ending of MW1 (and my memory doesn't fail me), what big events moved the plot in MW2? I just want to catch up on the story I missed, please don't say anything about the story of MW3.
In order words: spoil MW2 (but not 3) for me.