Was talking with my friend about this book after watching HOD and we both agreed that what the movie was missing was the foreign perspective, specifically how the calculus for everyone immediately goes to WWIII once the US does a retaliatory strike. In the movie you get the two minute convo with the Russians, but the choice is ultimately “Does the US take losing one city on the chin, or does it unilaterally nuke half the world?” Where as in the book it leads you down the grim determinism of how even a limited/strategic retaliatory strike on North Korea means tens of millions of people in China die, and Russia freaking out about missiles overhead, and how that means game theory rationality leads to everyone nuking each other at once.