Russia's swift annexation of Crimea created ripple effects that extend well beyond Ukraine, fundamentally redefining the relationship between Washington and Moscow.

Vladimir Putin's land grab undermined President Obama's so-called "reset" with Russia, leaving the White House appearing weak and incapable of deterring the Kremlin's aggression.

While Obama slowly expanded sanctions against individuals and laid the groundwork for hitting key sectors of Russia’s economy, critics questioned if he could land a counter punch that would draw blood.

Analysts said Obama is now operating in a completely different diplomatic world and will have to rethink his foreign policy assumptions.

“This is a game-changer for the future of the relationship with Russia,” said Olga Oliker, associate director of the International Security and Defense Policy Center and a senior analyst at the nonpartisan RAND Corporation. “Putin is not interested in how the U.S. and Europe view his neighborhood.”

“There’s no real easy answer here,” added a former Obama counterterrorism adviser. “It’s not as simple as ‘show strength.’ This is a period of flux in which he’s just trying to minimize damage. There’s no clear win.”

As former Defense Secretary Robert Gates conceded, Crimea will likely never revert back to Ukrainian control. It's now a question of how much further Putin is willing to go.

For a president who once mocked rival Mitt Romney’s suggestion that Russia was a major geopolitical threat, Obama is finding it difficult to stake out the middle ground between avoiding a new Cold War and punishing Moscow.

Obama and U.S. allies will try to devise an approach with teeth during a side meeting at a nuclear summit in the Netherlands. But the president’s preference for multilateral action could leave Russia undaunted if European allies are unable to coalesce around a response.

The president has already ruled out the prospect of intervening militarily in Ukraine, and there appear to be few tough options on the menu for Washington.

The U.S. is likely to propose sanctions that target Russian defense and energy companies, while working with partners to shore up Ukraine’s economy. The key is to create sanctions that hit Russia’s economy while not exposing European partners to unacceptable collateral damage.

Putin, now enjoying a resurgent popularity at home, sees little incentive to kowtow to Western demands. It's an attitude that is particularly worrisome for Russia's neighbors, who want protection against someone they view as a schoolyard bully.

“Putin has declared an open war against the current system of global governance,” said William Pomeranz, deputy director of the Kennan Institute for Advanced Russian Studies at the Woodrow Wilson Center.

“An unstable Ukraine causes problems for the eastern part of Europe,” he added. “It potentially enables and encourages Russia to continue in a more aggressive foreign policy.”

Obama dispatched Vice President Joe Biden to Eastern Europe, where he tried to reassure leaders the U.S. was committed to protecting its NATO allies.

Putin’s actions could also embolden leaders in Syria, North Korea and Iran. Already on the defensive over an increasingly volatile Middle East, the European turmoil raises the very real prospect that Obama's domestic agenda could take a back seat to putting out fires on the global stage.

So far, the president has tried to keep the attention on his domestic agenda, and has continued fundraising for Democrats ahead of November. Republican critics on Capitol Hill, though, say Obama neglected foreign policy and is now paying the price.

Obama’s own political allies could also force him to get more aggressive with Russia.

Hillary Clinton, the likely 2016 Democratic presidential frontrunner, has taken a decidedly more hawkish tone on Putin.

“If he’s allowed to get away with that, then I think you’ll see a lot of other countries either directly facing Russian aggression, or suborned with their political systems so that they’re so intimidated, they’re in effect transformed into vassals,” she said of Putin’s annexation of Crimea.

Obama has been relying on Putin to help him in Syria and Iran. The president saw the Kremlin as a central partner in keeping Tehran from developing nuclear weapons.

But with trust between Obama and Putin shattered, some analysts wonder whether the two leaders will ever effectively work together.

“Obama will have as little direct communication with Putin as possible,” Pomeranz said. “I don’t think he is going to go looking to consult with Putin on much of anything.”