The biggest foreign policy crisis of the Obama presidency has deepened under the weight of Russian leader Vladimir Putin’s ignoring of US sanctions, and the threat of more, and his annexation of Crimea in steadfast defiance of the West.
How the US moves beyond the financial sanctions imposed on 11 Russian and Ukrainian officials on Monday to punish the Kremlin for the "most blatant land grab in Europe" since the second World War, as Brookings Institution scholar Steven Pifer labelled the takeover of the Crimean peninsula, is the subject of feverish debate within political circles and foreign policy confabs in Washington.
The limited responses from the Obama administration so far have shown the inadequacy of such measures against a man intent on righting the wrongs of the recent history of the region, as illustrated by his speech to the Russian parliament on Tuesday, formally "reunifying" Crimea with Russia, that was laden with references to Moscow's past ties with the strategically significant peninsula.
Rhetoric
The US turned up the rhetoric dial with vice-president Joe Biden, on a visit to eastern Europe to reassure Nato countries bordering Russia of American support, describing Putin's "dark path"on Crimea and decision to annex the region as a "brazen, brazen military incursion" and a "blatant, blatant disregard of international law". The repetition of scolding adjectives is unlikely to force a reversal from the Russian leader.
Even though Putin said in his speech that he had no further designs on other parts of Ukraine, there is little trust in Washington in the statements emanating from Moscow.
Two weeks ago Putin said Russia had no plans to annex Crimea. On Tuesday he signed treaties annexing Crimea after it overwhelmingly passed a referendum on Sunday to leave Ukraine and become part of Russia – held in the face of strong protests from Washington and Kiev’s new pro-western government.
Fervour
Foreign policy analysts in the US calculate that Putin may require other parts of Ukraine to make the Russian occupation of Crimea viable. Emboldened by the absence of any really painful censure from the West that might outweigh the elation of recovering Crimea, and buoyed by nationalist fervour at home in response to Russia's expansion to the south, Putin may be eyeing other former Soviet areas such as Moldova's ethnic Russian Transnistria region.
"Russia has preoccupied itself for a long time with regaining lost territories," said Herman Pirchner, president of the American Foreign Policy Council, a Washington-based foreign policy think tank.
“They are not going to be easily dissuaded from trying to get more. It is a classic case of where eating feeds the appetite.”
The unpredictability of Putin's behaviour complicates matters for Obama. The US has ruled out direct military engagement and is seeking to reinvigorate Nato in eastern Europe to shore up defences against further Russian aggression. Nato secretary general Anders Fogh Rasmussen has been in Washington this week meeting US government officials.
Trade
On the economic front, applying harder-hitting sanctions by the US on Russia requires support from the UK, Germany and France, which rely far more heavily on trade with Russia than the US.
Given the interconnected nature of global trade, western companies face follow-through pain from any sanctions imposed on Russian energy giants such as Gazprom and Rosneft.
The Russian economy may be vulnerable to targeted responses such as banking restrictions on companies and individuals, and the international operations of Russian oligarchs, but Europe will not be as eager as the US on such moves, given the vulnerability of the euro zone economy.