The enlargement of the European Union and the North Atlantic Treaty Organization into Central and Eastern Europe (CEE) raised questions concerning the institutional architecture in Europe as well as the future orbits of the two organisations.1 As a result, the two processes were heavily politicised. Dual enlargement, as it came to be known, is of special interest to the study of the influence of the United States on EU security policies. The process was arguably the first time that the two actors interacted strategically on an equal footing on a major policy issue. As Geoffrey Edwards pointed out: “Elements over the debate on enlargement play into those on the very purpose, nature and scope of the ESDP, others exacerbate possible problems, including the relationship between the EU and NATO and the United states.”2