From what I've read, aside from Kevin Costner's character's "expanded role", which you can mentally edit out, most of the movie is pretty accurate as far as the confrontations between Hawks and Doves were concerned - although I suspect emotionally exaggerated for effect. The events in the movie are also pretty accurate, which makes "13 Days" one of the scariest movies I've ever watched because it's frightening how close we came to destroying the planet.