NATO Enlargement: Cost Estimates Developed to Date Are Notional

Pursuant to a congressional request, GAO reviewed the executive branch's estimate of the cost of expanding the North Atlantic Treaty Organization (NATO), focusing on: (1) the reasonableness of the study's key assumptions; (2) verifying the pricing of individual cost elements and identifying the basis for the pricing; (3) whether the estimate's major cost categories and elements should be ascribed to NATO enlargement; (4) factors that were not included in the study's cost estimate that could affect enlargement costs; and (5) comparing the executive branch's cost estimate with the Congressional Budget Office (CBO) and Rand Corporation estimates. GAO did not independently estimate the cost of enlarging NATO.