As if 2011 was not momentous enough, 2012 promises plenty more change. Thanks to the geopolitical impact of the 'Arab spring' and Europe's debt woes, the year just past may, over time, come to be compared with others, such as 1989 when the Berlin wall fell. We can already mark on our calendars a generational leadership transition in China, a presidential election in the United States and elections in South Korea. Hong Kong will also get a new chief executive. Like last year's big events, these will reverberate; unlike them, they will be orderly. But whoever is elected will need to deal with the fallout from 2011's disorder.
In the Arab lands, the regimes of despots and demagogues have fallen, with ramifications for diplomacy and foreign trade. Violent upheaval continues. The nuclear meltdown triggered by Japan's earthquake and tsunami has added urgency to the need to reconcile energy needs with climate change. Capitalism, weakened by the global financial crisis, faces a social and moral challenge from protesters camped on its doorsteps.
Then there are the deaths that have changed the map of global security. That of Osama bin Laden, 10 years after the 9/11 attacks on the US, has not ended the threat of international terrorism but has refocused efforts to combat it. That of Kim Jong-il, which brought the elevation of his inexperienced, twentysomething youngest son to the leadership of North Korea - an isolated, rogue nuclear power - prompted urgent consultations among world powers about its implications for Northeast Asian stability.
But for all this drama, the event that cast the longest shadow over prospects for world growth and stability is the euro-zone debt crisis. It has hit, or will soon affect, employment, social security and asset values both in the developed and developing world. The jury is still out on whether the euro zone's struggle to restore fiscal responsibility leaves enough room for the growth needed to calm jittery financial markets and lessen the economic challenges for the rest of the world.
Because of its dependence on exports to the West, particularly Europe, China is already facing slower growth this year - a sensitive time because of its leadership change. It needs European leaders to keep their economies expanding while the policymakers in Beijing try to manage an orderly rebalancing of economic activity towards greater domestic consumption and engineer a soft landing after reining in bank lending to curb inflation. The extent to which they succeed will weigh on the economic prospects for Hong Kong, where unrest over the widening wealth gap and unaffordable property is rising. In a sign of the seriousness of the city's situation, both the leading candidates for chief executive have signalled a more interventionist economic policy.