During World War I, the need to break the deadlock of trench warfare saw the rapid development of many new technologies, particularly tanks. Military aviation was extensively used, and bombers became decisive in many battles of World War II, which marked the most frantic period of weapons development in history. Many new designs, and concepts were used in combat, and all existing technologies of warfare were improved between 1939 and 1945.

The increasing importance of cinema in the early 20th century provided a new platform for depictions of military subjects. During the First World War, although heavily censored, newsreels enabled those at home to see for themselves a heavily sanitised version of life at the front line. About the same time, both pro-war and anti-war films came to the silver screen. One of the first films on military aviation, Hell's Angels, broke all box office records on its release in 1929. Soon, war films of all types were showing throughout the world, notably those of Charlie Chaplin who actively promoted war bonds and voluntary enlistment.
Examinees also receive a score on what is called the Armed Forces Qualification Test (AFQT). AFQT scores are computed using the Standard Scores from four ASVAB subtests: Arithmetic Reasoning (AR), Mathematics Knowledge (MK), Paragraph Comprehension (PC), and Word Knowledge (WK). AFQT scores are reported as percentiles between 1-99. An AFQT percentile score indicates the percentage of examinees in a reference group that scored at or below that particular score. For current AFQT scores, the reference group is a sample of 18 to 23 year old youth who took the ASVAB as part of a national norming study conducted in 1997. Thus, an AFQT score of 90 indicates that the examinee scored as well as or better than 90% of the nationally-representative sample of 18 to 23 year old youth. An AFQT score of 50 indicates that the examinee scored as well as or better than 50% of the nationally-representative sample.