Recent warnings about the threat posed by al Qaeda terrorists armed with Stinger shoulder-launched missiles ("Terrorists smuggle missiles into U.S.," News, May 31) is another reminder of how American weapons shipped abroad can come back to haunt us in unexpected and potentially tragic ways.
     Any Stingers currently in al Qaeda's possession probably date back to the Soviet invasion of Afghanistan, during which the CIA distributed more than 1,000 of the shoulder-fired missiles to rebels fighting the Soviets. Despite a decade-old buy back program, hundreds of these missiles remain at large.
     While certainly among the most troubling, the lost Stingers are only one of many examples of U.S. weapons and weapons technologies ending up in the wrong hands. The Israelis have repeatedly diverted U.S. missile technology to China. Iraq was able to improve the targeting system of its Scud missiles with the help of American technology obtained from the Brazilians.
     It is time to reconsider our role as the world's largest arms exporter. The lives of American soldiers and civilians may hang in the balance.
     
     MATTHEW SCHROEDER
     Research Associate
     Arms Sales Monitoring Project
     Federation of American Scientists
     Washington

Updated at 3:00 p.m.

Updated at 3:00 p.m.