The Supreme Court of Canada has just given the green light for British Columbia to force American tobacco companies to pay for smokers' past health care costs, even if the companies didn't themselves sell cigarettes in British Columbia. The companies can now be held retroactively liable in a foreign court for sales of cigarettes by third parties that were lawful at the time they were made. British Columbia is seeking to force the tobacco companies to pay it billions of dollars. The Supreme Court of Canada earlier approved British Columbia's suit against Canadian cigarette companies in a decision that I criticized in the National Post. That decision declared that there is no right to a fair civil trial under Canadian law, despite the guarantees written into Canada's Charter of Rights and Freedoms. Other Canadian provinces are now looking to cash in on the Canadian Supreme Court's disturbing ruling by bringing their own lawsuits seeking tens of billions of dollars from American tobacco companies. As the tobacco companies pointed out in their brief, the court's decision sets a bad precedent. Similar reasoning may now be used against other industries, such as automakers, which face lawsuits by state attorneys general over their alleged contributions to global warming. Industries in one state can now be sued by greedy officials in other states, leading to a divisive and destructive policy of beggar-thy-neighbor.