As Ukraine turns away from closer relations with the European Union and further into the embrace of Russia, the Obama administration is saying little about it or the resulting street protests, for fear of provoking a fracture with the Kremlin.

Huge street demonstrations in the Ukrainian capital that might have sent U.S. spokesmen to the ramparts just a few years ago have merited only mild and largely noncommittal statements, and a decision by Secretary of State John F. Kerry to skip a planned visit to Kiev this week.

The unrest has brought crowds of up to 300,000 people to the streets of Kiev, the Associated Press reported Tuesday. Demonstrators are angry that Ukrainian President Viktor Yanukovych will not sign an association agreement that would have deepened trade and other ties with the E.U., and will instead improve relations with Russia.

The crowd in Kiev’s Independence Square is the largest display of public anger since the 2004 Orange Revolution that had marked Ukraine’s firm but short-lived turn away from Russian influence.

The apparent reasons for the low-key U.S. response involve Russia, lately the U.S. partner in diplomatic deals involving Syria’s chemical weapons and Iran’s nuclear program. There is little percentage for the United States in making the fate of Ukraine a contest for influence with Moscow now. . .