Japan is one of the world's largest wood importers, with two-thirds of its imports as logs (unprocessed timber). Southeast Asia has been the largest log supplier, but supplies (and exports to Japan) have been declining. The United States has become a more important supplier, but concerns about declining domestic timber supplies have led to proposals to prohibit or to tax log exports. Opponents suggest that Japan would simply turn to other sources to replace U.S. logs. One question in this debate is where the alternative sources of logs or wood products might be.