UKRAINE'S DEMOCRATIC revolution has ended the way most do, with the victorious coalition dividing into factions that are now battling each other. For the most part, this is a healthy development. The Orange Revolution movement that overturned a corrupt and autocratic regime last year was united by the cause of democracy and independence from Russia. Once that was achieved, ideological and policy differences were bound to surface. In Ukraine's case, President Viktor Yushchenko, a moderate and market-oriented reformer, has finally split with Prime Minister Yulia Tymoshenko, who espouses populist and statist policies. No violence has accompanied their rupture, and a parliamentary election scheduled for March provides a good opportunity for the country to choose between them.

In the short term, the split may well help stabilize Ukraine's economy, which has been turbulent ever since the revolution. After firing Ms. Tymoshenko and her cabinet, Mr. Yushchenko nominated a respected technocrat, Yuri Yekhanurov, as prime minister. Mr. Yekhanurov, who is likely to win parliamentary approval, probably will put a stop to the disruptive populism that the previous government frequently pursued, including huge increases in spending and attempts to control commodity prices. He will also limit the renationalization of state industries that were privatized by the previous autocratic government; though many of these transactions were corrupt, the government's seizures and plans for resale have raised their own questions.

Like last year's presidential campaign, the parliamentary elections will present Ukrainians with stark and potentially disruptive choices. Mr. Yushchenko is likely to offer continued market reforms and integration of Ukraine with Western institutions but also good relations with Russia; the more charismatic Ms. Tymoshenko will rail against big business and promise more social spending. Russian President Vladimir Putin, who could not contain his glee over the government breakdown, will hope that the pro-Moscow politicians he so aggressively backed last year will somehow seize the advantage. Western governments can hope that Ukraine continues steps toward joining institutions such as the World Trade Organization and cleans up lingering corruption. But the most vital interest will be ensuring that, whatever the outcome, Ukraine preserves the democracy its people demanded and won.