WASHINGTON, D.C.: As America basks in an era of peace and security, the original significance of Memorial Day is easily obscured by the smoke of a backyard barbecue as families across the country gather to celebrate the first day of summer. But speaking Monday at Arlington National Cemetery in a tribute to fallen American soldiers, President Clinton urged the nation not to grow too complacent. Speaking to several thousand who had gathered amid the neat rows of small white tombstones, the President warned that America must meet its global responsibilities to avoid mistakes that led to past wars. "Today our generation has been given a precious chance to redeem the sacrifice and service, to build an undivided, democratic European continent at peace for the very first time in history." Clinton made his remarks just hours before leaving for France to sign the landmark Russian-NATO pact that stands to open a new era of cooperation in Europe. Some Americans, as well, tried to refocus Memorial Day on what it was meant to commemorate. In Salem, Oregon, the Chemewa Indian School held an all-night vigil around a watch fire, and veterans honored fallen soldiers by burning logs for them. In Wichita, Kansas, volunteers laid a 7-ton Great American Flag across two acres of a grassy field. And, in the nation's capitol on Sunday, thousands of vets on motorcycles rumbled down Constitution Avenue in their 10th annual "Rolling Thunder" rally, calling for better health care for vets and stepped-up action in the search for soldiers missing in action.