When did the Soviet Union collapse?

By the late 1980s the USSR faced a stagnant economy, costly military spending and rising independence movements in its 15 republics. Gorbachev’s reforms of glasnost and perestroika opened up debate but weakened central control. In August 1991 hard-liners attempted a coup, which collapsed after three days as crowds led by Boris Yeltsin resisted in Moscow. On 8 December the leaders of Russia, Ukraine and Belarus signed the Belovezha Accords declaring the Soviet Union no longer existed. Gorbachev resigned on 25 December, the Soviet flag was lowered over the Kremlin that evening, and the next day the Supreme Soviet formally voted the country out of existence.