Both Putin and the rest of the world are yet to be told what the consequences of Russia's incursions into the Crimea will be; so far the answer is "not very much". It is hard to see what deterrent there is for further Russian territorial seizure in Ukraine. Obama has missed the opportunity to lay down commitments or affirm America's security obligations. It remains to be seen if he can fashion a truly strategic response while caught in the maelstrom of tactical responses to the situation. Given that he has shown no predisposition to strategic thinking so far in his presidency, it seems unlikely that he will start now. America's rivals from Tehran to Beijing will be watching with considerable satisfaction.

The annexation of Crimea by Russia is simply the latest in a series of mismanaged geopolitical disasters where President Obama has failed to articulate any goals for the use of American power. Obama's lack of coherent strategy did not cause the crisis in Ukraine, but it certainly failed to prevent it. The result is that the strategic priorities for the rest of his term will be more complex, as Russia becomes a geopolitical spoiler.

Even before the crisis in Ukraine, 2014 had seen an inelegant flood of historical analogies with 1914, but as Ukraine witnesses America prevaricate over how to deal with Russia's regional ambitions, the question is whether we are entering a new Cold War. Historical analogies are inevitably difficult to sustain but nonetheless Obama's lack of strategic clarity is reminiscent of the dangerously vague "ententes" that paved the way for the First World War.

The nature of the US president's confused worldview became clear during his last election campaign. Obama seized on the writing of Robert Kagan, one of his opponent Mitt Romney's foreign policy advisers. Kagan's main thesis, set out in an article for the New Republic, was that ongoing arguments about America's decline were significantly overstated and that the world had not returned to the pre-Second World War situation of roughly equal great powers. Instead, Kagan, and by extension Obama, perceived a world of "uni-multipolarity". In other words, the US remained the sole superpower, with several secondary powers jostling beneath.

For Kagan, American power has always been a source of ambivalence for the rest of the world, even while it valued the US's regulatory function in times of crisis. America's decline or continued leadership had always been a matter of strategic choice for the president, regardless of outside opinion. Beyond the ivory tower, there is nothing particularly unusual about adopting Kagan's worldview. The problem is that Obama's political education occurred during the so-called "holiday from history", in the early 1990s. The immediate aftermath of the Cold War was a period of tremendous optimism. American power was unambiguously preponderant and triumphant. At the time it didn't seem to matter that President Clinton had no coherent grand strategy. There appeared to be no limits to Western democracy, which led to an unsophisticated enlargement of Nato. Obama was lulled into a false sense of security by the apparent teleology of Francis Fukuyama's notion of the "End of History", the seemingly inevitable march of liberal democracy. When coupled with Kagan's view of the relative balance of power and continued American preponderance, it is understandable why Obama thought himself free of the burden of making difficult strategic choices.

The Ukraine crisis illustrates that the stability and spread of democracy, which appeared certain 20 years ago, is gradually disintegrating. It is against this backdrop that Obama has failed to make the case for America's longstanding defence of the liberal world order.