Fundamentally speaking, the dollar's ( quote ) real challenge here is the prospect that a sustained oil shock will accelerate global inflationary pressures. In the United States in particular, the dollar is seen as vulnerable to the prospect that the Federal Reserve will effectively surrender to inflation in order to avoid raising interest rates before the last possible moment. Even a perfunctory interest rate hike could drive Greece, Portugal, Ireland or even Spain back into another funding crisis -- which would likely have a net negative impact on the euro down the road, to say the least.