Veterans of Gulf War have complained for years of a cluster of ill defined and often unexplained ailments they think are related to their service. Many believe that their wide ranging symptoms can be explained only by some hitherto undisclosed exposure to chemical weapons. But the symptoms attributed to "Gulf War Syndrome" have varied too widely to group into a recognized disease or to explain in terms of any known medical mechanims-even, scientists admit, by exposoure to any of the currently understood types of nerve gas. (editorial)