HONG KONG — American domination of the world economy was challenged last week at the Group of 20 summit in Seoul much the same way that Barack Obama's Democrats were mauled in this month's U.S. congressional elections, which the president termed a "shellacking."

Several countries took on the once almighty United States and declared that the leaders of a broken economy had no business trying to tell fast-growing countries what to do.

Dominique Strauss-Kahn, the managing director of the International Monetary Fund, gave a diplomatic summing up of Seoul, declaring: "This G20 was more of a G20 of debate than a G20 of conclusions." The failure to achieve anything more than bland promises like the patently untrue "pledge to continue our coordinated efforts and act together" raises doubts about the usefulness of the G20 itself.