This PhD thesis aims to devise a coherent and balanced legal regime for the protection of foreign investments during armed conflicts and occupation. The proliferation of armed conflicts in the MENA region and Eastern Europe in recent years has given rise to novel legal questions to which the investment treaty regime does not adequately and effectively offer an answer. To fill this gap, the thesis is divided into three parts. The first part examines the operability of investment treaties in times of armed conflicts. The second part proposes one of the possible approaches to dealing with a selected number of procedural questions, some of which have already arisen in the recent investment treaty arbitrations against Russia and Libya, while others could potentially arise in future disputes. The third and last part provides a nuanced interpretive framework for ascertaining the content of investment treaty standards considering their interaction with host state's obligations under international humanitarian law (IHL).