This is the kind of story Russell is best known for: a lone smart alec vs a less witful universe.
Story summary.In a galactic Union of many species & worlds, two particular ones - Drenes & Salamards - have been corroding the atmosphere by their constant bickering & minor fights, both driven by ambitious, unscrupulous & corrupt leaders.
Sebastian Snodgrass is an unconventional diplomat assigned by Terra to solve the problem. Very funny story.
Fact sheet.First published: Astounding, February 1958.
Download full text as part of the scans of Astounding (British edition), May 1958.
Among the stories from Astounding/Analog issues edited by John Campbell.
Related: Stories of Eric Frank Russell (annotated & ranked list).