This collection of essays by Professor Michael N. Schmitt of Durham University draws together those of his articles published over the past two decades that have explored particular fault lines in the law of armed conflict. They examine the complex interplay between warfare and law, seeking to identify where the law and warfare appear to diverge, and where such apparent divergence can be accommodated through contextual interpretation of the law. Each essay examines a particular issue in either the jus ad bellum (the law governing resort to force) or jus in bello (international humanitarian law) that has proven contentious in terms of applying extant norms to the evolving face of armed conflict. Among the topics addressed are counter-terrorism, cyber operations, asymmetrical warfare, assassination, environmental warfare and the participation of civilians in hostilities.