NOW that the tumult and shouting have died, it is worth looking at what the G-20 summit actually achieved.
Pittsburgh's role as host, providing the venue for the leaders to discuss important topics while making a good global impression, seems to have played out well.
If the real test of the G-20 is what the participants accomplished, however, two major unknowns remain. One is what the leaders said to each other in the person-to-person encounters they had here. We'll never know, for example, what President Barack Obama told Chinese President Hu Jintao about tires and chicken feet. Also unknown at this point is what the countries will do to carry out whatever pledges they made when they get home. That will depend on the individual political circumstances of each.
Looking at the "Leaders' Statement" and the various press conferences that attendees held after the summit, several important decisions were made:
•Henceforth, critical world economic and financial decisions will be taken by the G-20, as opposed to, in the past, the G-8. This adds Argentina, Australia, Brazil, China, India, Indonesia, Mexico, Saudi Arabia, South Africa, South Korea, Turkey, and the European Union to the G-8's Canada, France, Germany, Italy, Japan, Russia, United Kingdom, and the United States.
This is important in terms of giving the world's middle-sized economies a greater say in the big decisions. It was foolish on its face to have excluded China and India, for example, from top-level deliberations. Reflecting the shift, the June, 2010, summit will be hosted by Canada, while South Korea, a new player, will have it in November, 2010, and France in 2011.
•At least lip service was paid to continuing efforts around the world to see the global economy out of the past year's recession. Language about stubbornly high unemployment, however, was somewhat pallid.
•Reforms designed to prevent the repeat of a similar economic train wreck were discussed. Countries subscribed to a need for changes to the banking sector but, reflecting the disagreement among them - notably the United States and the United Kingdom and the other Europeans - there was little about regulation of banks and financial houses and, in particular, executive pay caps. It is no secret that Mr. Obama is loath to tackle this issue while he is trying to build support in the Congress for his health-care changes.
Coordination prior to the upcoming Copenhagen climate change conference received little attention. A pledge by the countries to phase out $300 billion in fossil fuel subsidies is relevant to that issue, if it is respected.
•Aid to poorer countries received some attention, with a reiteration of the G-8's previous pledge of $20 billion. Poorer countries will benefit from a reallocation of International Monetary Fund and World Bank voting shares in their direction.
•Trade, a sensitive topic, received little attention, except perhaps in the corridors.
In the end, the summit provided a good opportunity for the participants to talk. What action follows by the leaders remains to be seen.