Comment by ben_w

The reason everyone used carpet bombing in WW2 was the inability to aim competently. This even persisted after WW2, leading to some tests of air-to-air nuclear weapons just to give the missiles a decent chance to actually disable the target they were fired at.

The counter-strategies that the British used to defend against German strikes included "switch off all the lights at night so they don't know where they are" and "order newspapers to lie about which part of the city was damaged in order that spies reading British newspapers and reporting back to HQ said missiles fell short/went too far, causing HQ to incorrectly compensate on the next strike". I don't know if the reverse was true, despite now living in Berlin.

Everyone's supply chains were also much shallower, and equipment much cruder and therefore easier to make (though also less efficient). Half of London or Berlin losing electricity makes a much smaller difference when far less was electrified in the first place, e.g. loss of electricity for a heat pump doesn't matter so much when the terraces and apartment blocks have internal fireplaces and regular coal deliveries.

Also re Vietnam, it took until 1997 to return to the per-person energy use it had in 1970: https://ourworldindata.org/profile/energy/vietnam

And until 1993 to reach the not-adjusted-for-population level.

And the electricity graphs don't even go back far enough to see what that war was like, that's all energy.