This book is extremely well written, accessible, and interesting. It looks at the philosophical factors of who should intervene in response to humanitarian crisis including just war theory, motives, consequentalism, international law, and representativeness. For example is a humanitarian motive enough for a state to intervene in response to genocide when it's citizens do not want the intervention to take place? Pattison's book also looks at the current interveners, which are legitimate, and makes suggestions for the future.
I would highly recommend this book to scholars of international relations, just war theory, political philosophy, international law, politics, philosophy, humanitarianism, and war.