United States-Israel Security Assistance Authorization Act of 2018 This bill extends Military Financing Program grants for Israel through FY2023. The Department of Defense shall conduct a joint assessment with Israel regarding: (1) precision guided munitions needed by Israel in a sustained armed confrontation with Hezbollah and other armed groups and terrorist organizations, and (2) related U.S. assistance and resupply planning. The President may utilize the Special Defense Acquisition Fund to transfer precision guided munitions and related defense articles and services to reserve stocks for Israel. Authorities for loan guarantees and the war reserves stockpile for Israel are extended through FY2023. The Department of Homeland Security shall establish a seven-year grant program with Israel to support: (1) cybersecurity research and development, and (2) commercialization of cybersecurity technology. The U.S. Agency for International Development may enter into memoranda of understanding with Israel to advance common goals on energy, agriculture and food security, democracy, economic growth, education, and health. The National Aeronautics and Space Administration (NASA) shall continue to work with the Israel Space Agency to pursue peaceful space exploration and science initiatives. The President may enter into a cooperative project agreement with Israel to carry out research and joint production of defense articles and services to detect and destroy unmanned aerial vehicles (i.e., drones) that threaten the United States or Israel. The bill states that it is U.S. policy to ensure that Israel maintains its qualitative military edge.