By Ahmad Mukhtar is a producer for CBS News based in Toronto, Canada. He covers politics, conflict and terrorism, with a focus on news from Canada and his home nation of Afghanistan, which he left following the Taliban's return to power in 2021. Read Full Bio May 12, 2026 / 12:22 PM EDT / CBS News Add CBS News on Google Toronto —  The neighbors just aren't visiting the way they used to. A study by the University of Toronto suggests a roughly 42% reduction in visits to U.S. cities by residents of Canada last year. The drop  —  much steeper than official border crossing statistics suggest  —  is largely attributed to mounting political and trade tension between the two countries. By tracking cellphone activity, University of Toronto researchers found "a year-over-year median decline of approximately 42% in Canadian visits to U.S. metropolitan areas." According to official statistics , the number of Canadians who entered the country after returning from the U.S.…