So, if the United States were to dramatically increase its net savings to suddenly wipe out its fiscal and current account deficits, the global economy would likely head rapidly into recession unless other economies took immediate steps to reduce their net savings by increasing their domestic demand.
The other point to make is that the key to a smooth and orderly resolution of imbalances lies in letting market-based adjustment mechanisms work. After all, savings-investment imbalances occur all the time between regions in a single country, such as Canada or the United States. But these imbalances don't tend to cause problems, because market mechanisms help to resolve them.