In the Dune universe, when a laser weapons hits a shield, both are destroyed in a nuclear explosion reaction.
So instead of building nuclear weapons, wouldn’t it be easier to tie a timer and a “parachute” to a laser gun and drop it from orbit onto your enemy’s city?
For the fun of hard sci fi is theorizing the stupidly powerful shit. Playing with the in universe science.
In any case they wouldn’t even need to have parachutes, just fire the laser a moment before impact or build some kind of drone that had multiple lasers that fired simultaneously…. Big, big booms.