At more than 5,500 miles long (including Alaska), the U.S.-Canada border is the longest undefended border in the world. In many ways it is a series of contrasts with the U.S.-Mexico border, which receives much more political and personnel attention.

While the primary concern on the southern border is illegal immigration, the security focus on the northern border is strictly on terrorism, further heightened after the July arrests of 17 suspected terrorists in Ontario who were allegedly plotting to carry out attacks in Canada. And in another high-profile incident, Algerian terrorist Ahmed Ressam, the so-called “Millennium Bomber,” was arrested with a trunk full of explosives after crossing on a passenger ferry from Victoria, British Columbia, to Port Angeles, Washington. Ressam was planning to blow up the Los Angeles International Airport.

And while nearly 10,000 U.S. Border Patrol agents, recently bolstered by National Guard troops, work along the 1,900-mile border with Mexico, the 5,500-mile long (including Alaska) U.S.-Canada border is secured by barely 1,000 agents—and even that number has been a three-fold increase since 9/11. Local, state and federal officials all express concern about vulnerability on the U.S.-Canada border, due to a lack of funding and manpower to monitor the expansive territory.

Where much of the southern border is desert and scrub, the northern border is a rough and challenging array of mostly untamed terrain: the rugged mountains and forests of Washington; vast-stretching plains and farmland of Montana and North Dakota; meandering waterways, lakes and rivers in Minnesota, Michigan and elsewhere around the Great Lakes; and the rolling hills and gentle slopes of northern New York and Vermont, for example.

| The tough task of protecting the border has been aided to an extent by a post-9/11 technology push: remote cameras and sensors allow U.S. Border Patrol agents to monitor remote areas; gamma ray scanners and radiation detectors help U.S. Customs and Border Protection officers on the look out for nuclear weapons or other smuggled items through ports of entry in trucks or cars.

Overall however, the goal of bolstering security on the U.S.-Canada border comes with an additional challenge: to not hinder the flow of goods and commerce between the two countries. With $1.4 billion of goods per day ($500 billion per year) crossing the border, the U.S. and Canada are the two largest trading partners in the world. In addition, the two countries share a rather interdependent tourism industry, with millions of Americans and Canadians visiting eachother’s country every year.

This interdependent economic relationship can be seen even on the smallest of scales in border towns like Stanstead, Quebec and Derby Line, Vermont, where the border is simply a part of daily life. Residents of these neighboring towns frequently cross the border for goods and services not available any closer in their own country. On weekends, they may come together for an afternoon of theatre at the Haskell Free Library and Opera House, which has the unique position of straddling the international border: the book collection, theatre stage and first dozen rows of seating are in Canada, and the entrance, balcony and remaining seats are in the U.S.