The Global Positioning System (GPS) is a military space system operated by the U.S. Air Force that continuously broadcasts precise time signals. These signals can be used worldwide to aid position location, navigation, and timing. GPS is an information resource that supports a wide range of civil, scientific, and commercial functions as well as U.S. forces. National policy toward GPS has not, however, kept pace with the system's rapidly expanding international uses. This study identifies major opportunities and vulnerabilities created by GPS for U.S. defense, commercial, and foreign policy interests, and makes recommendations for U.S. policy toward GPS, including future governance and funding. If the United States promotes GPS as a global standard, it should address the dual-use nature of the technology through international agreements. If the United States becomes an unreliable steward for GPS, it risks losing the economic and diplomatic benefits from past investments in this technology.