[sandworm101]

>> Giant nuclear weapons are heavy, dirty, inefficient, and pointless

Pointless yes, but as bombs scale in size they actually become more efficient, burning more of their fuel. The primary reason behind this is that the cores of larger bombs maintain critical mass for a longer period of time before blowing apart, resulting in more fission/fusion per weight of fuel. So they are less radioactive, less dirty, than an equivalent number of smaller bombs.

[DmenshunlAnlsis]

The burn is potentially more efficient, but the bigger it is past a certain point, you’re just blasting that energy out of the atmosphere. I suppose burying or submerging a massive device would deliver more energy, but it would be supremely dirty in that case. Airbursts are the best way to attack drag-sensitive targets due to the formation of a Mach stem, and as a bonus they’re cleaner than water or ground bursts. If you really want to destroy a target use MIRVed warheads of lower yield, in the 70kt-1mt range, with overlapping shockwaves. As a “bonus” that technology already comes standard and doesn’t require new testing or exotic designs and delivery systems.