On October 27, the US Department of Defense released the declassified version of the 2022 version of the Missile Defense Assessment Report. The US media said that the report reaffirmed the primacy of US indigenous missile defense and highlighted the air defense and anti missile construction of Guam. As a programmatic document of the Biden government on missile defense, it is of great significance to guide the development of the US air defense and anti missile system. However, analysts generally believe that compared with the previous version, this report is still old tune and lacks a clear implementation plan. It is reported that this is the first time that the United States has simultaneously released the National Defense Strategy, Nuclear Situation Assessment Report and Missile Defense Assessment Report. The confidential versions of these three reports were submitted to the United States Congress in March this year. The latest declassified version has a total of 80 pages, including 17 pages of the Missile Defense Assessment Report. US officials said that the Biden government issued three reports at the same time, which is conducive to the US military taking a unified and coordinated approach in matters such as strengthening deterrence and risk management. In 2019, the Trump government released the last version of the Missile Defense Assessment Report. The 2019 version of the report maintained a high degree of continuity with the 2010 version of the Missile Defense Assessment Report, but for the first time, the missile defense plan was placed under the background of competition among major powers. The 2022 version of the Missile Defense Assessment Report largely reflects the current missile defense policy of the United States. In comparison, the new edition is somewhat "shrunk", with only 12 pages and 4700 words. In 2019, the internal text of the version released to the public was 100 pages, totaling 28834 words. The 2022 version of the Missile Defense Assessment Report is divided into five parts, namely introduction, the evolving air and missile threat environment, strategic and policy framework, strengthening international cooperation with allies and partners, and conclusions. The report particularly emphasized that the US military should pay attention to "a more comprehensive air and missile threat", with special reference to UAV systems. According to the report, UAV systems are cheap, flexible and consumable, and can carry out tactical attacks as well as large-scale attacks. According to the report, unmanned aerial vehicles (UAVs) have similar lethality to cruise missiles, can be launched from a wide range of areas and are difficult to find. In addition, opponents usually do not think that UAVs have the same attack effect as cruise missiles, making them the preferred equipment for tactical attack. At the same time, with the continuous development of the technology of unmanned aerial system, its application scope will be further expanded. In addition, new threats include space shuttles and partial orbital bombing systems that can enter and leave the atmosphere. According to the report, the United States will continue to develop active and passive defense systems against the threat of hypersonic missiles, and build a durable and resilient sensor network to detect and identify hypersonic weapons and intercept them. The primary task is the report on domestic defense, which reiterated that the domestic missile defense is the primary task of the United States missile defense. The United States will continue to upgrade and develop its land-based midcourse defense system. The system mainly includes 44 ground-based interceptors located in underground silos, most of which are deployed in Fort Greeley, Alaska, and a few are located in Vandenberg Space Force Base, California. In addition, the system includes space-based and ground-based sensing