BAE has described the rationale for expansion in the US; " is by far the largest defense market with spend running close to twice that of the Western European nations combined. Importantly, US investment in research and development is significantly higher than in Western Europe." When Dick Olver was appointed Chairman in July 2004 he ordered a review of the company's businesses which ruled out further European acquisitions or joint ventures and confirmed a "strategic bias" for expansion and investment in the U.S.