The United States is working on unspecified economic sanctions against Russia, but there's not much support from the allies.
The threat of economic sanctions has not kept Russia from taking a tighter hold on Ukraine's Crimean Peninsula.
Will Sparks is an analyst with the Eurasia Group, a leading political risk consultancy. Does he think the U.S. and Europeans are willing to let Putin keep Crimea?
"I don't think they much of a choice," Sparks said.
"The Europeans don't want a direct confrontation with the Russians because Europe draws 28 percent of its natural gas from Russia," he said.
Two-thirds of that gas travels in pipelines through Ukraine.
Germany gets 36 percent of its gas from Russia, Italy 27 percent, France 23 percent. The U.S. has little economic leverage; only 2 percent of its trade is with Russia.But Sparks said the West's most effective move would be to pump billions in economic aid into the new government in Kiev.
"It's not about sanctions. It's not about punishing Russia. It's about helping the Ukrainian government. Because frankly that's what the Russians are really worried about," he said.
Does Sparks think Putin has overplayed his hand?
"I do think he's miscalculated," he said.
"The idea that the Russians are going to win Ukrainian hearts and minds anytime for the foreseeable future is pretty much out of the question at this point. So arguably, what have the Russians gained? They've gained control of Crimea. They've shaken their fist at the West. But in terms of the long-term goal, it's hard to see how this serves Russian interests," Sparks said.
A wider conflict would be risky for Russia, too. It could disrupt the flow through those pipelines - and half of Russia's revenue comes from oil and gas.