Politics

Honestly a bunker like this is only useful as a tomb. There was a period in the 50s where nuclear bunkers made sense. The bombs were smaller and hitting within a mile was generally considered on target. But today? In a nuclear conflict, the White House would receive direct precision strikes by multiple bunker-busting thermonuclear bombs. Think of the bunker buster bombs already employed by nations to hit hardened targets, but make them thermonuclear.

In theory, if you dig arbitrarily deep, you could build something to survive. But even Cheyenne Mountain isn't expected to survive any nuclear war. Our hardened underground missile silos? The doctrine for their use is to make sure they launch before they can be hit. The bunkers just mostly protect them from conventional attacks.

It is just not possible to build something to survive a direct nuclear attack by modern weapons. Sure, if you could literally build something miles deep, it might survive. But any of the access tunnels and elevator shafts to that bunker would be obliterated in the attack. And there would be no practical way to excavate them and rescue people from such depths. All a miles-deep bunker would get you is a slow death via dehydration and suffocation.