Overseas Contingency Operations: Alternatives Identified to the Approach to Fund War-Related Activities, Report to Congressional Committees [open pdf - 540KB]
From the Document: "Since 2001, DOD has received more than $1.8 trillion in OCO [Overseas Contingency Operations] funds. DOD defines 'contingency operations' as small, medium, or large-scale military operations, while 'base' activities include operating support for installations, civilian pay, and other costs that would be incurred, regardless of contingency operations. Congress separately appropriates amounts for base and OCO activities into the same appropriation accounts and directs how funds are to be spent by designating amounts in conference reports or explanatory statements accompanying the annual appropriations acts. The National Defense Authorization Act for Fiscal Year 2018 included a provision for GAO [Government Accountability Office] to report on the feasibility of separating OCO expenditures from other DOD expenditures. This report describes internal controls that selected DOD components use to separately account for OCO and base amounts during budget execution and identifies and examines alternatives that Congress or DOD could use to separate funding for OCO and base activities."
Government Accountability Office: http://www.gao.gov/