the case for spaceplanes

there are problems that cruise missiles, fighter aircraft carrying missiles 

and bomber aircraft can't solve, 

but nuclear weapons can solve 

those problems could instead be solved by bomber spaceplanes carrying bombs and missiles with conventional warheads or more likely kinetic missiles 

and kinetic impact devices that get their speed from the bomber spaceplane's speed 

bomber spaceplanes would increase the amount of steps between comventional war and nuclear war