What ICF did was play off the weapons and the energy people. When one side raised questions about the validity of the justification for ICF from their side's point of view, the ICF people could just point to the other side.

I think in the end the real justification was maintaining a cadre of physicists who were familiar and experienced with the physics of materials at H-bomb like conditions, in case new generations of bombs needed to be designed, and also to help validate improved computer codes for simulating those conditions without actual bomb tests.