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?
It did for the Killing Star. Not nukes, but R-bombs which are probably the most insane WMD-s and unlike strangelet bombs actually feasible even at our current tech level. All you need is a light-sail and a big-ass solar-powered laser.
But, yeah, for dune: