Question: How could WOPR not know the difference between a game and real life?
Question: Since David told McKittrick that he thought he was only playing a game and at the time didn't know that he hacked into WOPR, McKittrick tells him that they're still on Defcon 4. Why would it still be on Defcon 4 instead of it going back to Defcon 5 after David confessed everything?
Answer: The assistant to McKitrict explains that US is waiting to go back on DEFCON once the Russians do so.
Answer: McKittrick doesn't believe David. He thinks he's covering for accomplices...most likely Russian spies.
Question: At the beginning of the film, who were the two men in uniform and why did one pull a gun on the other?
Answer: They were erroneously alerted that an actual nuclear attack was underway, and they had been trained to respond by firing a nuclear warhead. However, one was unconvinced that the US was actually under attack, and he wanted further confirmation from his superiors. The other insisted that they follow protocol and fire the missiles. One man alone cannot launch the missiles, it takes two, and the one with the gun is attempting to force his partner to follow through on launching the weapon.
Answer: Actually it would take four men; two men in two separate LCCs (Launch Control Centers) to corroborate. In fact, there are five LCCs in a Squadron and the others can even "inhibit" an erroneous launch order coming from a single LCC.
Answer: While wardialing every number in Sunnyvale, California to find the game company's number, he found a number that led to a back door into the WOPR.
Question: When Joshua calls David back, why doesn't David just instruct Joshua to "end game"?
Answer: The short answer to your question is that, had David instructed Joshua to "end game," and had it succeeded, there would be no movie. In context, at that juncture, he was just freaked out about being unable to lose the connection to Joshua. Further, he probably didn't try at that point because he did not yet realize the magnitude of what was transpiring. Recall it wasn't until later in the film that he even realized that Joshua didn't draw distinctions between fantasy and reality, or that the game was running to its logical conclusion with actual weapon systems. Had David even tried to end the game, it probably wouldn't have worked. Joshua had to learn the lesson of futility (playing tic-tac-toe) before abandoning the game's objective.
Answer: David couldn't tell Joshua this because he didn't know exactly how to end the game until the end of the movie.
Question: Can a general change the DefCon unilaterally?
Answer: It's unlikely. To my understanding, the DefCon level, which ranges from 5 to 1, with level 1 indicating almost imminent nuclear war, is changed by orders of the Secretary of Defense, in consultation with the U.S military joint chiefs of staff. In the film, it's probably safe to assume that General Beringer (Barry Corbin) was working under orders in consultation with higher-ups at the State Department, and had instructions as to what circumstances would warrant a change in the DefCon level, and given the authority to do so. In U.S History, our DefCon level has only been ordered to level 2 one time, during the Cuban Missile crisis. The 9/11/2001 attack on the World Trade Center and the Pentagon resulted in an order by then Secretary of Defense Donald Rumsfeld to DefCon 3. (source: http://en.wikipedia.org/wiki/DEFCON).
Question: In the first scene of NORAD where the technicians first notice the incoming missiles, some of the people start saying sentences with the word "confidence" in it. What does "confidence" mean (in relataion to the military)? Does it mean like how sure they are of something?
Answer: The term "confidence" in this case is referring to a statistical element such as confidence interval and confidence level. The discussion of this element is beyond the scope of this answer. Suffice to say, the term "confidence is high" is a terse way of stating that the confidence level as a percentage is 95% or higher and the data sampled (in this case, computing a probability that the attack is real) is accurate.
Question: When David is detained in that room, under armed guard, how exactly does he escape? You know, he found a tape recorder and tampered with that keypad entry system?
Answer: He got the door to open with the copied sounds off the tape recorder, then shorted out the door's entry system, walked out slowly while the guard was coming on to the nurse. David then got on the bus after certain NORAD employees who were not familiar with him mistook him for a tourist.
Answer: The keypad that controlled the door used an analog tone-based system, much like old analog telephones. The control system for the door listens for which tone is produced by the button press, and if it hears the correct sequence of tones, the door opens. That's why David feigned having to use the restroom; he was running the tape recorder that was hooked up directly to the system in order to get the guard to input the correct code so that the correct tone sequence would be recorded, which he then played back, tricking the control system into thinking he had pressed the correct buttons on the outside.
Question: Near the beginning of the movie, the man in charge of the WOPR is explaining to the President's advisor that the WOPR has already fought WW3, as a game, many times over. Why wouldn't the WOPR have already learned that Global Thermonuclear War would be unwinnable, as it learned near the end of the movie?
Answer: WOPR had not yet learned the concept of a no-win scenario until it was ordered to play Tic Tac Toe against itself at the climax of the film. Once WOPR understood that there existed certain games that literally could not be won, it then understood that nuclear war was one of those un-winnable situations after running a sufficient number of scenarios with this new concept in mind.
Question: How is it possible that David, as a fugitive, was able to get on a plane to Oregon without getting caught?
Answer: At that point, David's school friend, Jennifer, had met up with him. She could purchase their plane tickets under her name. Air travel security then was less stringent than in the post-9/11 era though it was after the D.B. Cooper hijacking when tighter rules had been implemented. Being a movie, facts and reality are often skewed to serve the storyline though it begs the question of how a minor, even in this era, could buy tickets without proper I.D. for David and where did she get that much money.
Question: In the opening sequence, the younger silo guy is about to shoot his partner for not turning his key as ordered. What would be the point of this? If they have to turn the keys simultaneously then how would killing the other guy help? You'd just have a dead guy with nobody to turn the other key.
Answer: But if he doesn't turn the key, they can't launch anyway. So threatening his life results in either a) his death, and nothing's different from him refusing to turn the key, or b) him giving in and turning his key.
Answer: The younger one threatening to shoot knows that if he kills the other guy, he cannot launch the missiles alone. He is betting that by threatening to shoot his partner, he will force him into complying with the order in order to save his own life. It's a situation where the older guy may or may not comply, but at least there's a chance.
Answer: The reason the missile launch crew is armed is to stop one from going rogue and trying to launch without permission. The scene where he threatens to shoot the other one for refusing to launch is dramatic, but totally untrue.
Answer: The opening sequence was a test and I think only the older guy didn't know it was a test. The younger guy actually knew it was a test and was there to threaten him with death as part of the test. Later we find out that 22% of missile commanders failed to launch. So the fact that the younger guy calls the other one "sir", makes it seem (to me) that the older guy was the missile commander and was the only one actually being tested. So when they kept saying "these men", I think they're referring to the commanders being tested and not the pair of men we saw.
Answer: While merely speculation, the WOPR is not alive and knows only what it's been programmed to do. It would have no concept of life or death, and as such would see no difference between the simulation and the real thing. That being said, an easy way to make it see the difference would be to program it to not waste physical resources. It would then see the use of all its actual warheads as less desirable.