unhistorical:

December 26, 1991: The Soviet Union is dissolved.

On Christmas Day in 1991, Mikhail Gorbachev resigned as President of the Soviet Union. The next day, the Supreme Soviet of the Soviet Union dissolved the USSR after sixty-nine years of existence, following the introductions of the reformative policies of perestroika and glasnost, the fall of the Berlin Wall, the withdrawal of Soviet forces from Afghanistan, and the Revolutions of 1989 that swept through Eastern and Central Europe and swept communist regimes out of power. In August of 1989, Poland nominated its first non-Communist prime minister since the 1940s. In March of 1990, Hungary conducted multi-party parliamentary elections and a direct presidential election; in October of 1990, East and West Germany reunified, after over forty years of separation, to become one Federal Republic of Germany. Czechoslovakia’s famous “Velvet Revolution” achieved, in late 1989, the dismantling of the single-party system. In mid-1990 Bulgaria held its first free elections in over fifty years after the Communist Party relinquished power, and a violent revolution in Romania ousted Nicolae Ceauşescu from power. 

On December 12, 1991, the Belavezha Accords went into effect; this agreement by Belarus, Russia, and Ukraine, established the Commonwealth of Independent States, which gained eight new members after the signing of the Alma-Ata Protocol. The Soviet Union was completely and officially dissolved by the Supreme Soviet on December 26, 1991, and Russia, as the largest and most powerful Soviet state, inherited the USSR’s debt, properties, and role on the international stage; Boris Yeltsin inherited Gorbachev’s office building and many of his powers. The sixty-nine-year-old Soviet Union dissolved into fifteen independent states: Estonia, Latvia, Lithuania, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan, Belarus, Moldova, Ukraine, Armenia, Azerbaijan, Georgia, and Russia.