I could imagine a wider “targeting” beam, fired so that a satellite overhead of the target site could catch neutrino scatter from the warhead. I don’t know wha

I could imagine a wider “targeting” beam, fired so that a satellite overhead of the target site could catch neutrino scatter from the warhead. I don’t know what ridiculous engineering would be required to get sufficient neutrino collection for that to work, on a satellite, but if the budget covered a 50GW neutrino beam it might stretch to that, too.