Michael Albert

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.

Michael Albert

Answer: David couldn't tell Joshua this because he didn't know exactly how to end the game until the end of the movie.

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).

Michael Albert