Will they go nuclear? To help understand how the world might end — or be saved — the BBC assembled a team of British former military officers and diplomats in a “war room” with a fictional doomsday scenario. Mirroring the unrest in Ukraine, an uprising of Russian separatists in NATO-aligned Latvia triggers an escalation that gets London vaporized. Then it’s up to the decision-makers to retaliate by launching submarine-based ICBMs. With the planet in peril, each player must decide whether to give in or unleash a barrage of nuclear missiles.