The Group of 20 is beginning to look more like the G-19 + 1 as emerging and rich countries alike accuse the United States of breaking a vow of unity.
This week's G-20 summit will require every bit of President Barack Obama's diplomacy skills after the Federal Reserve embarked on a new $600 billion bond-buying spree, sparking criticism from four continents that the U.S. central bank was ignoring the global repercussions.
Officials from Germany, Brazil, China and South Africa were among those expressing concern that the Fed's money printing could weaken the dollar, drive up commodity prices and send uncontrollable waves of investor cash into emerging markets.
If the G-20 fails to defuse these global tensions, it may heighten investor concerns that policymakers are drifting further apart, leaving the world economy vulnerable to another bout of upheaval.
Domestic politics and policies make Obama's job tougher. He arrives in Seoul for the Nov. 11-12 summit weakened by a crushing congressional election defeat for his Democratic Party. His primary task will be to convince his peers the Fed's actions do not run counter to a U.S.-led push for global cooperation to even out economic imbalances.
South African Finance Minister Pravin Gordhan said the Fed's move "undermines the spirit of multilateral cooperation that G-20 leaders have fought so hard to maintain during the current crisis."
German Finance Minister Wolfgang Schaeuble was less diplomatic. He called U.S. policy "clueless."
It was less than five months ago that G-20 leaders gathered in Toronto, talking in warm and fuzzy terms about "collective well-being" and "shared objectives."
"G-20 members have a responsibility to the community of nations to assure the overall health of the global economy," the leaders said in their closing statement in June.
"If we act in a coordinated manner, all regions are better off, now and in the future."
Since that Toronto meeting, the dollar has dropped 11 percent against a basket of currencies, driving up currencies in Japan, Brazil, the euro zone and elsewhere. The biggest exception is China, where the tightly managed yuan has gained a relatively modest 2 percent versus the dollar since late June.
Obama's response to G-20 criticism is expected to be that the world needs a healthy U.S. economy, and the U.S. economy needs healthier exports.
Fed Chairman Ben Bernanke himself said a strong U.S. economy was critical for the global recovery, and his central bank was well aware of the dollar's "special role" in the global economy and monetary system.
Indeed, G-20 members all seem to agree that the world needs a better balance between cash-rich exporters such as China and Germany and heavily indebted consumer countries like the United States. The difference lies in how best to accomplish that.
For emerging markets fearful that the Fed's flood of cash will swamp their economies, the United States does not seem to be keeping up its end of the "shared objectives" bargain.
That makes it harder for Washington to push for policy changes elsewhere, particular in Beijing, which insists the yuan is not the primary culprit behind big global trade gaps. Treasury Secretary Timothy Geithner's proposal to set numerical targets limiting current account imbalances was roundly rejected at a G-20 finance ministers meeting last month.
The Obama administration was the driving force behind a proposal adopted by the G-20 in Pittsburgh last year to promote more balanced global growth.
That framework may be the best bet for G-20 consensus at this week's Seoul summit.
Unlike Geithner's numerical targets, the framework for balanced growth calls for mutual assessments to ensure domestic policies don't disrupt global growth.
G-20 countries submitted their medium-term economic plans for International Monetary Fund review last month. Leaders may agree to keep this process going beyond Seoul, keeping the IMF as arbiter.
The Fund told the G-20 nations in June that if they adopt mutually supportive policies, they could raise global output by $4 trillion and create 52 million jobs in the medium term.
Unless leaders can put on a convincing show of cooperation in Seoul this week, those loftier economic goals may remain well out of reach.
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