By COLLEEN BARRY VICENZA, Italy - Tens of thousands of people marched through the northeastern Italian city of Vicenza under heavy police guard on Saturday to protest a planned U.S. military base expansion. The demonstrators, estimated by police to number 50,000 to 80,000, marched peacefully along the four-mile route as hundreds of policemen stood guard and helicopters hovered above. Some protesters wore T-shirts saying "Yankee Go Home" and others waved rainbow peace flags as the demonstration headed out from city's train station. It was not scheduled to pass the site of the planned expansion, where critics of the project keep...