Re: Research
How are you getting "nuke" out of this article? Yes, they talked about ground-penetrating weapons, but those tend to be thermoberic, not nuclear. Nukes are almost exclusively air-burst, Ground-burst nukes have potential to be too nasty even for the people that would set them off.
And if you think that ground penetrating projectiles have no civilian use, Think about how much easier(and cheaper) that could make bridge building. Or allow for better foundations/footings for buildings, houses.