Empire of the East

Some time in the future, a nuclear holocaust is averted by a computer named ARDNEH (Automatic Restoration Director – National Executive Headquarters), which initiates what is intended to be a temporary modification (later called "The Change") to the laws of physics to make nuclear explosions impossible. However, the enemy has a similar device, and when the two expanding wavefronts of The Change collide, the effect unexpectedly becomes permanent.