Brad DeLong has a great discussion of the opposing views on the coming dollar crisis.
More soon on this, but my one-sentence take is that the optimists believe that it is possible to generate as much US dollar liquidity as required to prevent a large increase in interest rates (despite a depreciation), without generating domestic inflation in the US. In this, they have recent US history on their side. The pessimists think that, sooner or later, this kind of policy will fail. In this, they have long-term history on their side