40% of world trade is invoiced in dollars

This is the problem much of the emerging market faces: The revenues are in the local currency, but the costs are in US dollars.

That paradigm has led to a drop in emerging market stocks and currencies this year.

The risk is that as the Fed raises interest rates -- and if the US dollar continues to climb -- that it worsens and results in poor global growth.

The WSJ today takes a closer look.