Why have markets been so volatile recently, and even over the past decade, dating back to the Asian crisis of 1997-98?

It's pretty simple, argues David Malpass, chief economist at Bear Stearns, in a superb article this morning. The value of the dollar -- the globe's key reserve currency and unit of account -- has been swinging wildly about. The dollar is the foundation of enterprise. A foundation must be sturdy and stable, or the investments, businesses, and trade we build on top of it can sway or even collapse. The dollar is central to all U.S. and global commerce.