As the Commander of all NATO global operations from 2009 to 2013, I was often asked what kept me awake at night. The answer is a single word: cyber. In this brilliant new book, renowned lawyer, scholar, security practitioner, and professor Antonia Chayes provides some very real ideas to deal with the looming tower of cyber security.

But this book does not stop with cyber issues. It is distinctive for its originality in making connections that others have not made. It is distinctive in its clarity in explaining to an audience concerned with current and emerging security issues that their focus must be not just on who is winning or losing but on how, in the long run, civilians and military must work together to deal with the irregularity of warfare, and the legality of all the actions taken to combat it. This is an ambitious, creative, and incredibly timely examination of three critical areas of national security policy that exist in “the gray” between war and peace. Ultimately, it is a primer on the profound national security challenges and responsibilities the United States faces in the twenty-first century. Despite its strength, the world's most powerful state still wrestles with a very real set of formidable and complex threats. Modern threats combine rigid ideology, agile technology, and global discontent in ways that have not only disturbed and destabilized bureaucracies and militaries but also call into question the validity and adequacy of legal frameworks, domestic and international. Chayes has chosen to explore a particular kaleidoscope of campaigns – counterinsurgency, counterterrorism, and cyber warfare – that the American government has undertaken to do battle in this murky terrain that is modern-day war making.

Chayes blends a rich review of the existing scholarship with an incisive examination of the current doctrine, law, and policy to give the reader a clear, detailed sense of what is working, what is not, and which questions must still be asked and answered. She weaves deftly between domestic legal and political concerns and questions of international jurisprudence and geopolitics. Uninhibited by standard siloed thinking on matters of war, peace, and politics, Chayes moves seamlessly from the heights of grand strategy and guiding principles to the arenas occupied by policy makers and lawyers and right down into the field where soldiers, NGOs, firms, and militants operate.