HISTORY United States 26 Military operations, Aerial 14 History 10 World War, 1939-1945 8 TECHNOLOGY & ENGINEERING 7 World War (1939-1945) 7 Air power 5 BIOGRAPHY & AUTOBIOGRAPHY 4 Bombing, Aerial 4 Military campaigns 4 Persian Gulf War (1991) 4 Persian Gulf War, 1991 4 Vietnam War, 1961-1975 4 Armed Forces 3 Command of troops 3 Generals 3 Military art and science 3 Military planning 3 Military policy 3 National security 3 Strategy 3 USA 3 Vietnam War (1961-1975) 3 Aeronautics, Military 2 Air warfare 2 Bombers 2 Great Britain 2 Luftkrieg 2 Military doctrine 2