In the past thirty years, the defense budget has gone through two buildups (the Reagan years and post-9/11) and one build-down (after the Cold War.) Despite fluctuating toplines, however, the services’ percent share of the budget has remained roughly equal.
The one-third per service breakdown isn’t exact, although nearly all discrepancies can be derived from more dramatic changes to the fourth component of the defense budget—Defense-wide. Nonetheless, the consistency of the trend over the past thirty years is certainly remarkable.
Whether splitting the budget equally among the services makes strategic sense is questionable. As we reevaluate defense priorities, and tailor the force structure to match those priorities, reconsidering the budget breakdown will be critical.
Source: DOD Comptroller FY 2012 Budget Briefing Book, Tables 2-1 and 6-10