President Obama left Europe armed with little more than threats against Russian President Vladimir Putin, raising concerns over his ability to deter the Kremlin from expanding its footprint beyond Crimea.

Obama trumpeted the exclusion of Russia from the Group of Eight nations, but Moscow responded with a collective shrug and showed no signs of heeding U.S. warnings to stand down in Ukraine.

The White House intended to isolate Putin during Obama's weeklong trip to Europe, but instead sent the message that the status quo in Crimea would not lead to additional punishment, leaving critics to wonder why Obama was unable to rally support behind more stinging sanctions.

“If I'm in Kiev, I'm very disappointed, and if I'm in Moscow, I'm chuckling again,” said Andrew Kuchins, senior fellow and director of the Russia and Eurasia Program at the Center for Strategic and International Studies.

“If the goal was to try to convince our European allies to support hard-hitting sanctions, the sanctions we announced would have very little impact on the Russian economy,” Kuchins added. “If you promise there will be some costs, you really ought to deliver some that will be real.”

Obama's trip to the Netherlands, Belgium and Italy was filled with rhetorical hits, accusing Putin of being on the “wrong side of history.” But in dismissing Russia as just a “regional power,” Obama suggested he is not much interested in understanding Putin's motivations.

Analysts said the White House would be mistaken to rely on moral arguments to deter Putin from flexing his muscle in Eastern Europe and that more concrete action is needed.

“I agree with the president that there is such a thing as moral high ground,” said William Galston, a senior fellow at the Brookings Institution and an adviser to former President Bill Clinton. “The problem is that the high ground doesn't defend itself.”

While Obama was quick to brush off the prospect of another Cold War, he declined to say exactly how the United States would punish Putin for redrawing international boundaries unilaterally and firing a warning shot at Russia's neighbors.

Obama alluded to wide-ranging sanctions against the Russian energy, banking and arms sectors but left the impression that such penalties would be triggered only if Putin moved forces into southern and eastern Ukraine.

As the White House has acknowledged, there is little public appetite for military intervention in Ukraine.

The risk for Obama, however, is that in failing to wield a bigger hammer against Russia's takeover of Crimea, the administration emboldens leaders in Iran, Syria and North Korea who have already shown an eagerness to test the president's resolve.

It's not just Obama's political enemies who are sounding the alarm on his handling of the Ukrainian crisis.

Obama's former Defense Secretary Robert Gates dismissed the White House response as “anemic,” and said the “gap between western rhetoric and western actions in response to out-and-out aggression is a yawning chasm."

And a senior aide to one Senate Democrat told the Washington Examiner that, “It seems like we're just waiting for Putin to make the next move.”

The president received ample criticism for declaring a red line on Syria before ultimately stepping away from punishing Bashar Assad for using chemical weapons. The White House has deliberately shied away from similar provocative language when lecturing Russia. Critics fear the president prefers to remain in a holding pattern, allowing the Kremlin's hold on Crimea to stand.

The administration insists that Obama is not content with the status quo in Ukraine — and Obama tried to dispel the notion that the U.S. would remain on the sidelines as long as Putin didn't stoke further tensions in a fragile Ukraine.

“To be honest, if we defined our interests narrowly, if we applied a cold-hearted calculus, we might decide to look the other way,” Obama told students in Belgium.

“But that kind of casual indifference would ignore the lessons that are written in the cemeteries of this continent,” he added. “It would allow the old way of doing things to regain a foothold in this young century.”

But some analysts accused Obama of not practicing what he preached.

When asked to describe the message Obama was sending to the Russian leader, Kuchins replied, “Please, please, pretty please, Mr. Putin, don't do this.”

NOTE: This story was published Thursday, March 27, at 9:56 a.m. and was updated Friday, March 28, at 11:54 a.m.