how the war started was that russian extremist- makarov wanted to start a war with the US so he goes to brazil and gets 'AMERICAN' weapons off alejandro rojas or alex the red then he goes back to russia and pvt allen goes undercover to try to get in makarovs army group thing. they go to the the international airport, kill the civillians and fsb- russian cops then at the end makarov kills allenand with his american weapon, russia thinks its america and declares war on them.
i think thats not wright but owell
i dont really know because i ithink i heared somwhere that shephard was working with makarov then double crossed him
i think he did actually because how did makarov know where he was at.
when somone reads this can they tell me the real storyline