Anyways... It seems to me that the entire single-player campaign's story built on a combination of action-movie "rule of cool" moments and WTF style narrative missteps. The action-movies sections are pretty obvious with the, but not limited to, the snowmobile part of the Cliffhanger level.
The story problems are real problem, though. The terrorist level is just the first of several. The part where the terrorist leader fingers the "western nation" is logical, but the following "Crimson Sunrise" stage happening less than (narratively speaking) two days later just doesn't make sense. An event of that magnitude is a logistical nightmare that would have to be months in the planning to pull off in that short of a timespan, on top of the various political implications, which go unnoticed even during the between stage cinemas. And the writers did nothing to capitalize on this. Instead, the first of those "Crimson Sunrise" stage feels like a surreal attempt to shock people with the setting of the level. The way the narrative is written it doesn't support the events in any logical way, and because of it the seriousness of the, up to that point, potential plot is hampered.
The act 2 stages play everything in a direction that I'd expect though, and are, in my opinion, the best part of the game, but then act 2 closes with the biggest flaw in the entire plot, the betrayal. The bad-guy character is still the bad-guy, but character you're working for decides to off the players for absolutely no reason. I understand his action-movie character motivations, but the betrayal makes no sense on any level. And then the final act completely forgets that the bad-guy is the target and instead sends you after the betrayer, leaving it all open to use the bad-guy in a future MW as the new recurring villain.
So my point is this, IW writers seem to have jumped the shark with their writing. Admittedly MW1 had its action-movie moments, but they made sense within the story, and the story itself was played straight and serious, with most of the events being on a logical progression. MW2's story just didn't make sense to me, with most of the events taking leaps of logic usually seen in popcorn action-movies, but not in a game that is trying to be thematically serious like this.