What the film essentially does is offer us a clearly partly-fictionalised but fairly true to the events account of the thirteen days of the Cuban Missile Crisis in 1962. It's a fascinating close-up on a fascinating man, who might have been a truly great president if he had gotten a proper chance. Of course, the filmic portrayal of JFK may be just a tad overly sympathetic, and the treatment of the military a tad overly harsh, and the importance of Kenny O'Donnell, played by Kevin Costner, is probably exaggerated, but these are minor quibbles. What this film really does is show us just how complicated and multi-faceted was the problem of Russian nuclear missiles being installed in Cuba. Not only did the president have to face the dim and distant threat of a faceless Russian bureaucracy, he had to deal with the multiple and conflicting options constantly being advanced to him, the dangers posed by certain special interests in military and intelligence and the popular opinion of the American people. The repercussions of any number of different courses of action were almost unthinkable. Tilting the hand seemingly in the American favour in one place, say in Cuba, would destabilise another danger zone, such as Berlin. Despite the fact that we all know how the events played out in the end, it can't be denied that this film keeps adding to the tension constantly, occasionally letting off a little and then piling on a whole lot more. It's a wonderful portrayal.
At its core, however, the film is an intelligent study of the ultimately paralysing effects of power, and the stark horror of mutual destruction as made possible by the harnessing of atomic power. The discovery of nuclear fission reactions has forever changed the face of warfare, because there now exists an ultimate solution so terrible it is almost beyond contemplation. In the comparatively safer times in which we now live, it is easy to forget how possible, perhaps even likely, the threat of nuclear war. America was then, and remains now, the most powerful nation on the planet, and yet a single wrong move could have ended all that, and at the cost of millions of innocent lives. Bearing the weight of decisions which could cost so much must have been a horrible burden to Kennedy, and, if nothing else, we should thank our lucky stars that he didn't buckle under the multifarious pressures placed on him. This film is a tribute to reason over hotheadedness, and peace over war. We should not forget the lessons that time has to impart, and if this represents a way to remember, then everyone ought to watch it.