High above the rugged border, an unmanned Predator B drone equipped with night-vision cameras and cloud-piercing radar has scanned the landscape for signs of smugglers, illegal immigrants or terrorists.
Armed agents checked the identification of border crossers while radiation sensors and other devices monitored vehicles entering by road. Soon, a network of telescopic and infrared video cameras mounted atop 80-foot metal towers will rise above key locations.
The beefed-up border security is not taking place along America's chaotic southern border -- riven by drug smuggling, gun running and illegal immigration -- but rather, its traditionally boring northern boundary with Canada.
The changes have jarred communities along the 3,987-mile frontier, the longest undefended border in the world.
"Those of us who grew up here never considered it to be a border," said Bernadette Secco, a communications consultant on the Canadian side of Niagara Falls who sometimes dines or shops in the U.S. three times a day. "We're neighbors, not terrorists."
The U.S. has increased security along the Canadian border since the Sept. 11 attacks. But changes are coming more quickly now, driven by fears of terrorists exploiting the relative quiet of the northern border and complaints that the U.S. has been disproportionately soft on Canada.
Homeland Security Secretary Janet Napolitano made the get-tough policy clear in recent comments.
"One of the things that I think we need to be sensitive to is the very real feeling among southern border states and in Mexico that if things are being done on the Mexican border, they should also be done on the Canadian border," Napolitano said at a March conference in Washington on border issues.
"In other words, we shouldn't go light on one and heavy on the other," she said.
Because Mexico, Canada and the U.S. share "one continent" -- as well as the North American Free Trade Agreement to promote trade and investment -- the secretary said, "there should be some parity there."
Before February 2008, the northern border was so open that an oral declaration of citizenship was sufficient to enter the United States.
Starting June 1, however, U.S. authorities will require anyone crossing from Canada to present a valid passport or a secure travel ID card. That has prompted protests from some residents along the border, who say a way of life is ending.
