I can't remember the name of the story, but in it a character in a remote Alaskan outpost during a war between the US and the Chinese (or Russians, can't remember). This sentry makes a discovery that allows the US to destroy any combustible.
The protaganist, Larry Hulser, was a chemist before being conscripted, and while he's on duty in an observation post he realises there is a way to detonate explosives remotely. The US adopts the technology, but the implication of the story is that it doesn't prevent wars - it just stops them being fought with explosives. The epilogue to the story is a quote (from an imaginary future history):
Many people labor under the misapprehension that the discovery of the Hulser Detonator was made in a secret government laboratory. In actuality, the genius of Dr. Lawrence Hulser was first seen on the Arctic battlefields of 1972 where he conceived his idea and where that idea was immediately recognized.
Beecher Carson, “The Coming of the Sword—A History of Ancient and Modern Wars”—Vol. 6, p. 112