The CIS or Confederation of Independent States, is what became of the Soviet Union after a failed coup to remove Gorbachev led to the rise of Boris Yeltsin, and the breakup of the Soviet Union into 15 independent states. Recognizing that despite their differences and resentments there was still some need to cooperate with other former Soviet republics, the CIS was formed.
The CIS faced a number of large challenges. Chief among them was how to maintain control over the large Soviet nuclear stockpile the independent nations had inherited. Ukraine and Kazakhstan, with some financial incentive from the United States, got rid of their stockpiles. There was conflict between a number of Russian minority populations in the CIS states, as years of pent up resentment of the native populations now came out into the open.
The biggest challenge though was taking each state from a government-controlled, centrally planned communist economy to something like a capitalist, western-style one. It had never been done before. It was chaotic to say the least, and as the instability of the various countries and currencies ran its course, the CIS had to deal with huge inflation rates and the emergence of an emboldened organized crime element that came to be the government in some places.
The Red Army was shattered by defections and budget cuts, so the individual states had to recreate their own defense forces.