THIS IS NOT a good weekend to hold a presidential election if you are not American and would like to have the attention of the United States and its major allies. Nevertheless, Ukrainians are due to go to the polls today for a presidential vote of enormous importance not only for their own country but for the future of Europe. One of the leading candidates in this nation of 50 million proposes that Ukraine align itself with the capitalist democracies of the European Union and NATO. The other would lead the country toward renewed integration with Russia under the neo-authoritarian politics of Vladimir Putin. The result will likely determine whether Ukraine preserves its fragile democracy and independence; it may also govern whether Europe slips toward a new divide between a democratic West and a Russian imperium.

In a free and fair election, Ukraine's choice would not be in much doubt: For more than a year polls have shown the pro-democracy opposition candidate, Viktor Yushchenko, with a substantial lead. But Ukraine's campaign has been anything but clean. Government-controlled media have openly campaigned for Prime Minister Viktor Yanukovych, while slandering his opponent. Thugs have broken up opposition campaign rallies. Most disturbing of all was the mysterious and nearly fatal illness that recently sidelined Mr. Yushchenko for several weeks. He claims, plausibly, to have been poisoned by government agents. Thanks to these and other manipulations, it appears likely that the election will be forced to a second round on Nov. 21. A recent poll showed that only 12 percent of Ukrainians believe the ballots will be counted fairly.

Many Eurasian countries have held problematic elections, but Ukraine's has been distinguished by massive external intervention from Russia. According to reliable sources, Mr. Putin has channeled hundreds of millions of dollars into the campaign of Mr. Yanukovych. Russian political advisers have flocked to Ukraine, and Mr. Putin himself spent three days in Kiev this past week, during which he appeared on all three of Ukraine's national television channels to praise the official candidate and presided with him over a Soviet-style military parade. Mr. Yanukovych has pledged to end Ukraine's bid for NATO membership, make Russian an official language, allow for dual Russian-Ukrainian citizenship and integrate Ukraine into a Moscow-dominated "single economic space."

The Bush administration's reaction to these events has been weak. Officials have expressed concern: Deputy Secretary of State Richard L. Armitage said in an article published Friday that "there are signs of trouble" with the elections and that the United States has "an overriding interest in a democratic Ukraine." Yet no U.S. official has publicly noted, much less criticized, Mr. Putin's heavy-handed attempt to install an autocratic client as the president of a country that historically has been the starting point for Russian imperialism. Such silence will only encourage Mr. Putin and his Ukrainian allies to press forward with a project that begins with the disenfranchisement of Ukrainians -- and could end with the redivision of Europe.