China has imposed punitive trade measures on U.S. firms, including Raytheon, Boeing, and Lockheed Martin, to protect national security interests. This includes adding 28 companies to an export control list and banning exports of dual-use items to them. Additionally, 10 firms were placed on an "unreliable entities list" related to arms sales to Taiwan, which restricts their business operations in China. These actions, largely symbolic, could heighten U.S.-China tensions just before President-elect Trump takes office, who has advocated for tariffs and sanctions on China.