If China or Russia recovers before the USA, place bets on systemic war. Or, at the very least, a massive shift of power and lots of proxy wars. I don't see it happening, one of the graces of the financial crisis is that it hit everywhere within a few months and so, while reducing overall economic output, it has in essence preversed the current status quo. But depending on who does what, challenges to US primacy in Eastern Europe, Central Asia and SE Asia may be more common. Russia is already relying on quasi-5GW techniques (hackers, lawfare, energy resources) to force US allies to become less enthusiastically supportive of the country. But since Russia is essentially an energy company with an army right now, they may factor in the economic costs of such a conflict and shy away. China is sticking with the USA for now, but there is only so much shit they will take. Their use of populist elements in the country is going to bite them in the ass sooner or later, and could eventually force them to move in unexpected and unpredictable ways - ones which may not be in the interest of the USA or Japan.