U.S., Western Allies Agree to Boycott G-8 Summit in Russia

At the New York Times, "Russia Is Ousted From Group of 8 by U.S. and Allies."

And at the Washington Post, "Obama, allies agree to boycott Group of Eight meeting in Russia, isolating Vladi­mir Putin":

THE HAGUE — The world’s major industrial nations on Monday effectively suspended Russia indefinitely from the Group of Eight and warned that they would impose stronger economic sanctions against Moscow if President Vladi­mir Putin expands his military intervention in Ukraine.

The decision followed a push by President Obama for a united stand by wealthy nations against what he has called Russia’s violation of international law with the annexation of Crimea this month. Obama and the leaders of six allied nations — Canada, France, Germany, Italy, Japan and Britain — agreed Monday to boycott a planned G-8 summit meeting in Sochi, Russia, in June, effectively isolating Putin. Instead, they said they would convene as the Group of Seven in Brussels during the same time frame...

More.

A decision like this might have had more effect had it been imposed a month ago. Frankly, sanctions aren't likely to alter Putin's path, although a firm response now could give the West more influence in future iterations with Russia.