This is a long shot similar to what Joe White wrote above about theoretical physics as the basis for shutting down weapons. But this sounds a little bit like the 1978 novel by James P. Hogan The Genesis Machine. While not Asimov, Hogan had a technical background in engineering and was known for writing relatively "hard" science fiction in a style some might compare to Asimov.
"In an America becoming repressive in the face of world tensions, Brad Clifford, a young mathematical physicist, had been virtually drafted from academia to work on defense projects. But Brad's true dedication was to bring about the unification of all fields and forces, and his theory was too wild for his superiors to take seriously. So he defied the political authorities and went AWOL to work with a fellow maverick scientist. They built the machine that his theory made possible - but the machine made all weapons impotent, and could either wreck the world or save it. And the Powers That Be wanted to control it for their own benefit......"
The part that seems to match the most is that during the ending of the book.The protagonist instead of delivering an unassailable nuclear arsenal to the military, manages to build a computer/weapons system that is self-sustaining and will automatically destroy any nuclear weapons which are launched. This ultimately
allows the nations of Earth to stop the cold war and focus on using the new physics property to reach out to the stars.