Short answers, pulled from the story.
The Soviet Union officially dissolved on the 25th of December 1991. A series of treaties between newly independent states divided up the military's assets, and some units stationed in these republics swore loyalty to their new national governments.
General Colonel Pavel Grachev became the minister of defence in May 1992. He was made Russia's first Army General upon assuming this post while Marshal of Aviation Yevgeny Shaposhnikov served as Supreme Commander until his staff was abolished on the 15th of June 1993.
The First Chechen War was a rebellion by the Chechen Republic of Ichkeria against the Russian Federation that lasted from December 1994 to August 1996. The conflict ended with a ceasefire declared by Boris Yeltsin's government following widespread demoralization of federal forces caused by Chechen guerrilla warfare.
The Russo-Georgian War took place in August 2008 following worsening relations between Russia and Georgia. Significant reforms called New Look were announced on the 14th of October 2008 by minister of defence Anatoliy Serdyukov to address bad coordination, malfunctioning equipment, and friendly fire issues.
Russia launched a full-scale invasion of Ukraine on the 24th of February 2022 after Vladimir Putin announced a military operation at approximately 06:00 Moscow time. On the 21st of September 2022 during the ongoing invasion Vladimir Putin announced the first mobilization of citizens being conducted on a compulsory basis.