<p>On the afternoon of September 11 2001 the Irish Prime Minister (Taoiseach) Bertie Ahern ordered the 'heads of the security services of key government departments' to undertake a complete re-evaluation of measures to protect the state from attack. Hence underway within hours of the 9/11 outrage in the United States was potentially the most far-reaching review of Irish national security in decades. <br><br>This book the first major academic investigation of Irish national security policy as it has operated since 9/11 provides a theoretically informed analysis of that re-evaluation and the decisions which have been taken as a consequence of it up until September 2008. In so doing it draws on unprecedented access to Ireland's police security and intelligence agencies; over twenty senior personnel agreed to be interviewed.<br><br>Theoretically the author demonstrates the utility to the analysis of national security policy of three conceptual models of historical institutionalism governmental politics and threat evaluation. <br><br>The text is of interest to scholars of Security Studies International Relations and Politics as well as state and NGO personnel journalists and general readers.</p>