The U.S. is cutting off financial and technical assistance for an increasing number of weapons development projects done in cooperation with  Israeli companies. These include the F-35 aircraft, the Arrow 2 anti-ballistic missile and the Tactical High Energy Laser project. The United States is not happy with the degree to which Israel is selling American military technology to China. Israel has received hundreds of billions of dollars in military aid from the United States over the years, and a lot of that was in the form of military technology that Israel was allowed to use as a basis for developing additional weapons and equipment. But Israel had to agree to safeguard the underlying American technology secrets. Israel has not been doing this with China, which is notorious for stealing technology any way it can. Israel and China say that U.S. tech is not being shipped to China. American intelligence agencies and the Pentagon say the Israelis and Chinese are lying. The Israelis admit they need the sales to China, because in a post-Cold War world, there arent as many customers for military technology as there used to be. Jobs, and votes for Israeli politicians, are more important than the possibility of American troops getting  killed by Chinese weapons using stolen (via Israel) American technology.