Japan is in the midst of a rapid increase in tobacco-related disease mortality, following the rapid growth of smoking after WWII. Stomach cancer was the country's leading cause of cancer death for most of the 20th century, until lung cancer took over this position in 1993. Cigarettes are the major cause of lung cancer in Japan, but the country's leading manufacturer, Japan Tobacco, two thirds of which is owned by the Japanese government, continues to question whether tobacco is a major cause of disease and death. Japanese courts do not have the power to subpoena a company's internal records, which has made it difficult to document Japan Tobacco's strategies concerning tobacco and health. Our interpretation of online archives of internal documents from American tobacco companies, however, is that Japan Tobacco has long known about the potential health risks involved in smoking and has sought to obstruct effective tobacco control. Beginning in the mid-1980s, these efforts were often co-ordinated with American tobacco manufacturers. The documentary evidence shows that cigarette manufacturer Philip Morris in particular assisted with and sometimes also supervised Japan Tobacco's actions and statements on smoking and health. In one instance, data gathered for an article published by the Japan Public Monopoly Corporation (Japan Tobacco's predecessor) were deliberately altered to lower the reported value of a hazard indicator (nicotine concentration in the air). International collaboration has made it easier for companies such as Japan Tobacco to develop effective anti-antismoking strategies. Evidence of such global industry collaborations might grow as lawsuits begin to be filed in other nations.