When scholars look at major military operations throughout the course of history, they may note Hannibal crossing the Alps, Caesar's Gallic wars, the Battle of the Bulge, the invasion of Normandy, and similar interventions which have had major effects on mankind. One U.S. operation which began during the war in Vietnam continues today and reaches out to every overseas unit of our nation's armed forces. It involves millions of civilians, tens of thousands of employees of the U.S. Postal Service, and military logistical planning that would have dumbfounded Hannibal and Caesar. And it was all the brainchild of advice columnist Abigail Van Buren, known to her millions of fans and readers as "Dear Abby."