This chapter offers perspectives on the development of the internal U.S. government debate on NATO's transformation and enlargement and how these initiatives pursued by the George H.W. Bush and Clinton Administrations supported a common strategy to shape a new post-Cold War security order in Europe. It is written from Stephen J. Flanagan's vantage point as a member and later Associate Director of the U.S. State Department's Policy Planning Staff 1989–1995, National Intelligence Officer for Europe 1995–97, and the Senior Director for Central and Eastern Europe at the National Security Council Staff 1997–99—during accession of the Czech Republic, Hungary, and Poland to the Alliance.