The US wants the fast growing nations including China and India and Brazil to take the lead role in cutting down green gas emissions. With the current economic turmoil, US is already bleeding with nearly 10% of the people without jobs. So it is not possible for it to contribute to gas emission controls for the next one or two years.
Hence it is expecting fast growing countries to take the initiative and work on reducing the ozone layer damage.
The fact though remains that India and China contribute to less than 10% of the global gas emissions.
Whether it is fair to expect the developing countries with lower contribution to the problem, to take the lead role is a logical question which needs to be answered first.