gundamexplored:

“In U.C. 0080, with the fall of A Baoa Qu and the destruction of the Zabi family, the Principality of Zeon became a republic and concluded a peace agreement with the Earth Federation government.

“For the Earth Sphere, the six years between the end of the war and U.C. 0086 were a time of even greater confusion than during the war. Although the Zeon forces had been defeated, they still possessed greater military strength than the Federation Forces”

– from the ‘MS Encyclopedia’