Although the Vietnam War was the first war which space forces supported, the Gulf War has sometimes been referred to as the first space war because of the crucial role that space forces played in supporting land, air, and maritime forces. Prior to the Gulf War, most space forces were focused on strategic nuclear deterrence, not on support to tactical forces. Space forces, specifically satellite communications forces, had been providing support to tactical forces during the 1982 Falklands War, the 1983 United States invasion of Grenada, and provided real time mission planning data to strike aircraft in the 1986 United States bombing of Libya. The first use of the Navstar Global Positioning System occurred in the 1988 Operation Earnest Will, and during the United States invasion of Panama, Air Force Space Command provided communications through the Defense Satellite Communications System and weather support through the Defense Meteorological Satellite Program. In contrast, the Gulf War utilized the full range of U.S. space forces, with over sixty satellites providing 90% of theater communications and command and control for an army of 500,000 troops, weather support for mission planners, early warning of Iraqi Scud missile launches, and navigation support to terrestrial forces.