KIEV, Ukraine — AT this very moment, in plain view of the entire world, the final demise of the Soviet empire is unfolding. The plan for its resurrection, long in the works at the Kremlin, has failed: Ukraine has proved that it has matured into an independent state that will determine its own domestic and foreign policy.

It was when Viktor F. Yanukovych, then president, refused to listen to the pro-European yearnings of Ukrainians that the mass protests erupted in Kiev in the fall of 2013. It was when Mr. Yanukovych decided, with the active support of Russia, to resort to force that he lost control of the situation. And it was when Mr. Yanukovych crossed the line and unleashed gunfire against his own people that he lost his legitimacy as the president.

The Kremlin had a strategy designed to weaken Ukraine and its government by prying some regions away from Kiev’s control and establishing enclaves in the south and east similar to Transnistria in Moldova and Abkhazia and South Ossetia in Georgia. Russia needs these frozen conflicts in order to prevent the normal development of the post-Soviet republics and to impede their integration into European and NATO structures.

Moscow’s plan has been foiled. The people of Ukraine proved stronger than a dictator who had been groomed for the role of a puppet ruler. The opposition quickly gained control of the situation, consolidating the authority of Parliament and legitimately appointing a new government. This prompt action calmed the protests within the country, yet it also prompted foreign aggression.