The Proliferation Security Initiative (PSI) is an alliance of eleven nations (Australia, France, Germany, Italy, Japan, the Netherlands, Poland, Portugal, Spain, the United Kingdom, and the United States), for the purpose of coordinating and using their commando, naval and air forces to track, and seize, and ships being used by terrorists. Twelve times, in the last 13 months, exercises have been held. In most cases this consisted of ships and warplanes maneuvering to find and board a ship playing the terrorist vessel. Australia hosted the first of these exercises, off the coast of Australia last year. In October, 2004, Japan hosted the latest one, off Japan. This exercise involved nine ships from Japan, the United States, Australia and France. The activities of the PSI have impressed 65 other nations enough that they want to be involved. The initial eleven members have the most resources to actually do something about terrorism on the high seas, but the interested nations can provide information about activities in their waters, and that is apparently leading to an information sharing network that covers the planet.