Based on a quick search, here's what I discovered. Based on the available information, here's an assessment of Phillip J. Corso's credibility, rated on a scale of 1 to 10, with 1 being least credible and 10 being most credible: Reasons Supporting Credibility: Military Career and Accolades: Corso served for 21 years in the U.S. Army from February 23, 1942, to March 1, 1963, reaching the rank of Lieutenant Colonel. He had overseas tours in the European and Mediterranean theaters, as well as the Far East Command and US Army Europe​​. Education and Training: Corso had two years of college education and completed various intelligence and artillery courses​​. Awards and Decorations: He was awarded the Legion of Merit and other commendations for his service during World War II and the Korean War​​. Positions Held: Corso held various positions, including Battalion Commander of an Air Defense Battalion in Europe and Chief of the Special Project Branch at the Headquarters, AFFE​​. Reasons Detracting from Credibility: Limited Tenure in Key Roles: Corso was Chief of the Foreign Technology Division (FTD) for only 90 days, and during this time, he was absent for 15 days. This short tenure casts doubt on the extent of his influence and knowledge in this role​​. Unclear Association with National Security Council: There is ambiguity about Corso's exact role and membership within the National Security Council during the Eisenhower administration. He may not have been a direct member but possibly part of the staff or associated committees​​. Controversial Claims in His Book: Corso's book "The Day After Roswell" contains extraordinary claims about reverse-engineering alien technology from the Roswell crash. These claims lack substantive evidence and are met with significant skepticism and criticism for their inconsistencies and factual inaccuracies​​​​. Overall Rating: Given the mix of credible aspects of his military career and the highly controversial and unproven nature of his claims regarding extraterrestrial technology, I would rate Phillip J. Corso's credibility at around 4/10. This reflects a balance between his documented military service and the lack of concrete evidence or widespread acceptance of his more extraordinary claims.