THE ENCOURAGING news from Ukraine is that a crucial presidential election planned for Sunday is likely to go forward in much of the country, and to be free and fair. “The legal framework, administrative capacity and political will in place suggest that a democratic process will be feasible in the vast majority of polling places,” said a report Monday by the National Democratic Institute, which has deployed an observer team. “Candidates have been able to campaign with minimal interference, the media [are] pluralistic and there have been few formal complaints about election law violations or pressure on voters.”

At the same time, it is already clear that in two eastern provinces, where 14 percent of the electorate lives, balloting will be next to impossible, thanks to forcible disruption by Russian-backed militants. The United States and its European allies have said they will impose additional sanctions on Russia if it disrupts the election or fails “to use its influence to prevent those efforts,” as White House spokesman Jay Carney put it last week. Six days before the election, that failure is blatantly evident.

“There is intimidation,” a senior U.N. official told the Reuters news agency in describing the eastern regions of Donetsk and Luhansk. Ivan Simonovic, the assistant U.N. secretary general for human rights, said that a number of presidents and vice presidents of local elections commissions had been abducted or otherwise mistreated. Reuters reported that the last election commission attempting to operate in the city of Donetsk shut down Monday, leaving no voting operation in an urban area of 1 million people. Concluded the interior minister of Ukraine’s interim government: “It will be impossible to hold normal elections over the huge territory of Donetsk and Luhansk regions.”

Russian President Vladi­mir Putin seems to think that he can avoid responsibility for the disruption with rhetoric that suggests the opposite of Moscow’s actual behavior. For the third time, Mr. Putin announced Monday that the 40,000 Russian troops deployed on Ukraine’s border were withdrawing; for the third time, NATO’s secretary general and the White House said they had detected no such movement.

The empty announcements may at least mean that Mr. Putin has set aside the option of an overt military invasion of eastern Ukraine for the time being. But dozens of operatives of Russia’s military intelligence service have been spotted in eastern Ukraine, where they have directed takeovers of government buildings. Mr. Putin could use those forces to clear the way for Sunday’s voting, or at least withdraw them and their sophisticated weapons so that the Ukrainian army could clear the remaining rebels. He has made no move to do so.

In the coming days, the focus of U.S. and other Western officials will be, appropriately, on supporting the staging of the elections. Negotiations between the interim government and representatives of the eastern regions are also worth encouraging, though they appear unlikely to produce results in the short term. But President Obama, German Chancellor Angela Merkel and other E.U. leaders must also confront the reality that the latest “red line” they drew for Mr. Putin has been ignored. That must lead to the consequences they have promised: meaningful sanctions on the pillars that prop up the Russian economy.