This book analyses the multi-faceted impact armed conflict has on investment treaties. Making a case for the continuity of investment treaties, it rejects the common doctrine on the termination and suspension of agreements due to armed conflict that alleges rules outside general treaty law. The book shows that the effects of armed conflict on such agreements go far beyond questions of treaty continuity. Changed factual circumstances and public interests as well as international humanitarian law heavily influence the application and interpretation of investment protection standards. This pertains not only to cases of physical violence but also to emergency measures adopted by host states. The book argues that investment treaties can channel these effects, remain effective during armed conflict, and strike a fair balance between investor and public interests. It shows ways in which contextual and systemic interpretation, respect for reasonable state action, and careful treaty design can ensure that investment treaties continue to fulfil their purpose of strengthening compliance with legal rules also in times of armed conflict.