There is, it seems, widespread consensus that the war on terror has been a profound failure. As Andrew Mumford succinctly notes in his chapter, 'the direction of the American-led "War on Terror" since the invasion of Iraq in 2003 has led to a tangible increase in the threat posed by transnational networked Islamist insurgents' (p. 42). Indeed, the recent plethora of emotively titled books - such as Fiasco, The End of Iraq, Winning the War Losing the Peace, Why We Are Losing the War on Terror - is illustrative of this negative consensus. The big loser, it seems, is the US; indicatively, according to Paul Rogers, 'the first six years of war on terror have shown the idea of the New American Century boosted by the war on terror to be something of a lost cause'. 1 Whatever one's views on the moral rectitude of the US, the fact that the world's primary superpower has failed so spectacularly must be cause for concern. While the prospect of US imperialism is clearly unappealing to most, the alternatives - a return to a multi-polar world similar to that which existed at the beginning of the 20th century, or the spread of Islamic fundamentalism - are hardly palatable. This book has explored the issues exposed by the war on terror with a more general focus on navigating a way out of the present mire towards a more secure system regulated by an effective legal regime informed by universally agreed ethical principles. If this is ever to be realised we must be clear as to the nature of the threat posed by al Qaeda, the role and efficacy oflaw, and the ethics which guide both our actions and our aims.