Report on the Historical Record of U.S. Government Involvement with Unidentified Anomalous Phenomena (UAP), Volume I

This document, Volume I of the All-domain Anomaly Resolution Office (AARO) Historical Record Report (HR2), provides a comprehensive review of United States Government (USG) involvement with Unidentified Anomalous Phenomena (UAP) from 1945 through October 2023. Mandated by the National Defense Authorization Act for Fiscal Year 2023, the report aims to investigate past USG-sponsored UAP efforts and address claims that the government has recovered and is hiding off-world technology and biological material. AARO conducted extensive research, including reviewing classified and unclassified archives, interviewing approximately 30 individuals, and partnering with Intelligence Community and Department of Defense officials. The report concludes that there is no empirical evidence that any USG investigation, academic-sponsored research, or official review panel has confirmed that any UAP sighting represented extraterrestrial technology. Instead, AARO assesses that the vast majority of reports are the result of misidentification of ordinary objects, natural phenomena, or experimental national security programs. The report details the history of various UAP investigatory efforts, including Project SAUCER, Project SIGN, Project GRUDGE, Project BLUE BOOK, and more recent initiatives like the UAP Task Force (UAPTF) and the Advanced Aerospace Threat Identification Program (AATIP). AARO notes that many interviewees who claimed knowledge of hidden UAP programs were actually referring to authentic, sensitive national security programs that they misunderstood or had incomplete access to. Specifically, the report addresses and disproves claims regarding the existence of official UAP nondisclosure agreements, the recovery of extraterrestrial spacecraft, and the reverse-engineering of alien technology. AARO also investigates the 'KONA BLUE' proposal, a failed attempt to establish a UAP recovery program under the Department of Homeland Security, and concludes that it was never approved. The report highlights that cultural, political, and technological factors, including the secrecy surrounding Cold War-era experimental programs, have contributed to the persistent belief that the USG is hiding extraterrestrial evidence. AARO emphasizes that while many UAP cases remain unsolved due to a lack of actionable data, there is no indication that these cases represent off-world technology. The report serves as a foundational document for AARO's ongoing mission to identify and mitigate risks posed by UAP to domain safety and to characterize potential competitor technological systems.