the Egyptians recognized that despite their improvements, they were defeated in the end, and became doubtful that they could ever defeat Israel militarily. Therefore, a negotiated settlement made sense to both sides. Many in the Arab world were outraged at Egypt's peace with Israel. Sadat, in particular, became deeply unpopular both in the Arab world and in his own country. Egypt was suspended from the Arab League until 1989. Until then, Egypt had been "at the helm of the Arab world". U.S. military doctrine U.S. military studies of the Yom Kippur War played a major role in shaping U.S. military doctrine in subsequent decades, particularly because the U.S. Army's Training and Doctrine Command (TRADOC) was established only three months before the onset of the war. U.S. Army Chief of Staff Gen. Creighton Abrams, TRADOC Commander Gen. William E. DePuy, and other Army leaders saw Israel's strategic and doctrinal conditions between 1967 and 1973 as similar to NATO's position in Europe, and thus they undertook a deep study of Israel's warfighting in 1973 to derive insights for war against the Soviet Union. Soon after the war, U.S. Army civilian analysts and senior officers such as Gen. Donn A. Starry visited the IDF and compiled "lessons" for the Army to learn after the war. These lessons covered the improved lethality and accuracy of anti-tank and anti-air missiles, the importance of superior training for tank crews, the necessity of cover and concealment during movement, and the importance of combined arms warfare. In 1976, TRADOC revised the Army's FM 100–5 Operations field manual and promoted an operational concept of "Active Defense", with a strong emphasis on tactical proficiency tied to the performance of advanced weapons systems like those observed in the Yom Kippur War fighting. Gen. DePuy visited Israel in 1976, where he toured Yom Kippur War battlefields and observed Israeli field training. He used these insights to encourage reforms of U.S. Army training to ease the Army's transition to a more professional force after the end of the military draft in 1973. In May 1977, Gen. Starry (soon to succeed DePuy as TRADOC commander) returned to Israel and toured Yom Kippur War sites on the Golan Heights, guided by Raful Eitan and Moshe Peled. Starry used his observations to address problems left unaddressed by the Active Defense doctrine, such as how best to fight follow-on echelons after the first battle. TRADOC's 1982 revision