For both countries, the level of trade with the other is at the top of the annual combined import-export total. Tourism and migration between the two nations have increased rapport, but border security was heightened after the September 11 terrorist attacks on the United States in 2001. The U.S. is approximately 9.25 times larger in population and has the dominant cultural and economic influence. Starting with the American Revolution, when anti-American Loyalists fled to Canada, a vocal element in Canada has warned against US dominance or annexation. The War of 1812 saw invasions across the border. In 1815, the war ended with the border unchanged and demilitarized, as were the Great Lakes. The British ceased aiding Native American attacks on the United States, and the United States never again attempted to invade Canada. Apart from minor raids, it has remained peaceful.