As Russia decides where to draw its new boundary with Georgia a reckoning will be due - among the people of Georgia living amid the wreckage of a failed gamble, and among their Western allies suddenly confronted with diplomatic impotence. But for Barack Obama, a different kind of reckoning is taking place: what happens when the formidable political instincts of the probable next US president meet the limits of his experience in national security.

From everything he has said and written, it is evident that Mr Obama, uniquely among leading US politicians, understands the new contours of global affairs - that the world won't be divided into neat categories of democracies versus autocracies, nor will it converge toward a Western model.

He knows instead, that a world of parts is emerging - of states drifting farther away from each other into a global archipelago of interests and values; and that in an archipelago world, appeals to freedom, democracy and human rights must compete with aims of stability, resource security and the projection of national power.

And yet, as the Georgian conflict spirals into a global crisis, Mr Obama finds himself on the back foot. Initially hesitant in his response to Vladimir Putin's expedition in South Ossetia, he has had to ratchet up his rhetoric in response to John McCain's for-us-or-against-us stance.

This is, as Obama the politician would know, a loser's game, even if Obama the statesman is still finding his way. Trying to outmuscle Mr McCain will invite only contempt among his foes and bewilderment among the millions of his supporters yearning for a different kind of US engagement with the world.

Georgia is only the most recent augury of a new era of zero-sum diplomacy for which the West is ill-prepared. The West's surprise at Russia's response was disconcerting enough. More troubling was the outdated assortment of threats with which it has tried to sound tough. Among the suggestions was a boycott of the 2014 Winter Olympics hosted by Russia, denying Russia membership of the World Trade Organisation and excluding it from G8 meetings. A common thread links all three: they are as difficult for the West to achieve as they are unlikely to alter Russia's behaviour.

Obtaining an Olympic boycott six years after the crisis in Georgia will be extremely challenging. Barring access to the WTO just after the collapse of the Doha talks may be less of a sanction than it sounds.

The G8 threat is even less convincing, although it is telling evidence of a 20th-century mindset that is oblivious to international changes. Before Georgia it would have been hard to find anyone seriously arguing for the importance of G8 meetings (Canada and Italy are members; China is not); much less that being denied entrance could be construed as leverage with a great power.

Far more important to the future of international diplomacy was a little-noticed meeting in Yekaterinburg, Russia, last May. There, for the first time, foreign ministers from the so-called Bric countries (Brazil, Russia, India and China) met to advance their common agenda in a world hitherto defined by Western rules. The Brics are expected to overtake the combined GDP of the G7 by 2035, and laid down a marker that they will not wait for reform of the post-Second World War institutions to be heard.

Does this mean that China or India will take Russia's side against the West? Not necessarily, but it does suggest a more complex interplay of interests in future. Strategic leverage will have to be earned - crisis by crisis, interest by interest.

Where Iran is concerned (to cite the West's principal pre-Georgia concern), it ought to be apparent that our interests are not identical with those of China, India or even Saudi Arabia. China must balance its concern over Iran's destabilising behaviour with its need for secure oil supplies. Russia will weigh its unease with Iran's nuclear programme against its interest in counteracting US dominance in the Gulf. And Iran's Arab neighbours are hedging their preference for US hegemony in the Gulf with the knowledge that the Persian presence is for ever while distant empires come and go. To gain the support of each of these for any effective policy of containment, concessions must be granted - in the region or elsewhere.

Which brings us to the real lesson of the Georgian debacle: Tbilisi's freedom to challenge Russia had already been traded away by its Western allies - whether they realised it or not. When Kosovo declared independence in February, a senior European official remarked that the West would pay a price for its decision to offer recognition in the face of fierce Russian opposition.

Specifically, he noted that it was likely to happen at a Nato meeting when the Ukrainian and Georgian bids for membership were to be discussed. He was right. At the April meeting, their applications were put on the back burner, demonstrating to Moscow that for some Nato members there was such a thing as a legitimate Russian sphere of interest.

The lesson is not that the West was wrong to recognise Kosovo or that Nato was right to delay Georgia's membership. Rather, it is to suggest that we increasingly live in a world of choices. We may be able to enjoy the satisfaction of supporting the Kosovans or encouraging the Georgians, but we may not be able to do so without paying a price in another arena.

If this appears daunting, imagine the time not too distant when China, Brazil, India and a dozen smaller but significant powers begin to align strategic aims with economic power in their dealings with the West. Avoiding a global zero-sum game will require a President Obama as shrewd as he is inspiring.

Nader Mousavizadeh served as special assistant to the UN Secretary-General Kofi Annan in 1997-2003. He is the editor of the Black Book of Bosnia

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