Analysis of the FY 2021 Defense Budget from the CSIS Defense Budget Analysis program provides an in-depth assessment of the Trump administration's request for national defense funding in FY 2021. The analysis addresses overall trends in the defense budget, changes in the FY 2021 request, and issues for Congress and the next administration to consider. It also covers the budgets of the National Nuclear Security Administration and the Space Force.

Except in a few instances, since World War II no American soldier or sailor has been attacked by enemy air power. Conversely, no enemy soldier orsailor has acted in combat without being attacked or at least threatened by American air power. Aviators have brought the air weapon to bear against enemies while denying them the same prerogative. This is the legacy of the U.S. AirForce, purchased at great cost in both human and material resources.More often than not, aerial pioneers had to fight technological ignorance, bureaucratic opposition, public apathy, and disagreement over purpose.Every step in the evolution of air power led into new and untrodden territory, driven by humanitarian impulses; by the search for higher, faster, and farther flight; or by the conviction that the air way was the best way. Warriors have always coveted the high ground. If technology permitted them to reach it, men, women andan air force held and exploited it-from Thomas Selfridge, first among so many who gave that "last full measure of devotion"; to Women's Airforce Service Pilot Ann Baumgartner, who broke social barriers to become the first Americanwoman to pilot a jet; to Benjamin Davis, who broke racial barriers to become the first African American to command a flying group; to Chuck Yeager, a one-time non-commissioned flight officer who was the first to exceed the speed of sound; to John Levitow, who earned the Medal of Honor by throwing himself over a live flare to save his gunship crew; to John Warden, who began a revolution in air power thought and strategy that was put to spectacular use in the Gulf War.Industrialization has brought total war and air power has brought the means to overfly an enemy's defenses and attack its sources of power directly. Americans have perceived air power from the start as a more efficient means of waging war and as a symbol of the nation's commitment to technology to master challenges, minimize casualties, and defeat adversaries.

Based on large-scale trends regarding Air Force planning over the 25 years from fiscal years 1962 to 1986, this report compares inputs--in the form of defense resources--with posture outputs--such as alert strategic warheads, tactical fighter squadrons, airlift ton-mile potential, etc. After examining important trends in Department of Defense and Air Force budgets, the author provides an overview of the historical Air Force posture and budget. He then presents close-ups of strategic, general purpose, and deployment capabilities. The research suggests that, over time, the enterprises that comprise the total U.S. defense effort have substantially converged, driven mainly by fiscal reality.