Nearly three months after Russian mercenaries and Russia-backed proxies began grabbing parts of eastern Ukraine in April, Ukraine's armed forces have made important breakthroughs against the occupiers. Significantly, the forced retreat of these Russian proxies on Sunday from Slovyansk and some other insurgent-occupied cities was chaotic. Some insurgents simply dropped their weapons and have been trying to escape to Russia or the Crimea region of Ukraine, which remains firmly in Russian hands. Others have merely fallen back and redeployed in rebel-held Donetsk and Luhansk, provincial capitals in Ukraine's eastern Donbas region.

As a result, today some three-quarters of the territory of the Donbas and nearly half of its population is back under the control of the Kiev government. Ukraine's forces have reportedly captured large amounts of weapons and ammunition, including anti-aircraft weapons with documentation and operating instructions indicating their origins in Russia.

Ukraine's deputy defense minister, Adm. Ihor Kabanenko, told me in Kiev last week that Ukraine has sealed most of its border with Russia. Now the Ukrainian government is moving quickly in the formerly occupied cities to provide services such as medical care for the sick and elderly. It is resuming payments of pensions and wages that were interrupted by the insurgent takeovers. Television reports from independent Ukrainian channels make clear that as emergency supplies of food arrive, the population—earlier portrayed as pro-separatist by Russian and other media—is not hostile to Ukraine. A poll taken last week by the Kiev International Institute of Sociology showed that in the Donbas, Ukraine's President Petro Poroshenko now enjoys more trust than either Russia's President Vladimir Putin or the insurgents.

Russian media have also changed their tone markedly since the Ukrainian counteroffensive began to make major progress in mid-June. There has been a sharp decline in the use of terms like "fascist junta" to describe Ukraine's government. Some Russian media outlets have even reported on the humanitarian relief efforts by Ukraine's forces.

Even before this week's military gains by Kiev, influential Russian opinion makers had begun to prepare the public for a Kremlin stand-down. On June 21, the nationalistic Russian film director Nikita Mikhalkov used his program on the Rossiya 24 TV channel to indicate that Russia cannot intervene in Ukraine without United Nations approval and that such support is not forthcoming. The patriarch of the Russian Orthodox Church, Metropolitan Kirill, said on June 17 that the fighting in Ukraine's east was an "internecine conflict" in which neither side could make a Christian "just war" claim.