Russian natural gas finally flowed into Europe once again Tuesday, after Moscow and Kiev pulled back from an energy war that drastically reduced supplies to many nations for two tough winter weeks. But the resolution looked more like a cease-fire than a permanent peace, with no guarantee against renewed hostilities between Russia and Ukraine, two former Soviet neighbors with sharply contrasting views of the future. The experience of the last two weeks has left many in Europe bitter toward both and eager to sever an energy lifeline that leads to the gas fields of Siberia. The 27-nation European Union gets about a quarter of its gas from Russia. Russia's gas monopoly Gazprom began pumping gas into Ukraine around 10:30 a.m., spokesman Boris Sapozhnikov said by telephone from the Sudzha metering station on the border with Ukraine. Ukraine's state gas company Naftogaz confirmed gas flowed through Sudzha, Pisarevka and other gas metering stations on its eastern border. Several hours later, gas began pouring across Ukraine's western border into Slovakia, Hungary, Bulgaria and Moldova - some of the nations hardest hit in the dispute. Supplies also returned to normal in Austria. Russia halted the supplies on January 7 amid a dispute with Ukraine over 2009 gas prices, alleging that Ukraine was stealing gas destined for Europe. Ukraine disagreed, saying Russia was not sending enough "technical gas" to pump the rest toward Europe. More than 15 nations in the Balkans and eastern Europe were left scrambling for alternative energy sources. Thousands of factories shut down for lack of fuel and millions of people shivered in unheated homes. The EU - dismayed when a deal sending monitors to key pipeline junctures failed to get gas flowing - marked the renewed deliveries with relief and remonstrations. "It was utterly unacceptable that European gas consumers were held hostage to this dispute between Russia and Ukraine," European Commission President Jose Manuel Barroso said. "We must not allow ourselves to be placed in this position in future." Barroso said before the dispute was ultimately resolved, Russian Prime Minister Vladimir Putin and his Ukrainian counterpart, Yulia Tymoshenko, had "systematically" vowed to end their dispute but then reneged. "I will not forget that," he told reporters. Many in the Balkans and eastern Europe won't forget it, either. Slovakia was forced to ration gas, favoring homes and hospitals, and forcing about 1,000 companies to halt or limit production. Impoverished Moldova switched to heating oil for power plants, and its people stockpiled bread and built wood fires to stay warm. Serbia and Bosnia, at odds for years, came together as Serbia shared some of its own precious gas supplies to help Bosnia cope.