This thesis examines the international legal framework that governs the protection of foreign investments in times of armed conflict. It addresses the laws of armed conflict and the international law of foreign investment and their regulation of investments in particular situations. The thesis provides an overall argument that the potential for conflict between investment law and international humanitarian law is a significant issue of growing relevance, as the two regimes, through their different norms, may regulate the same conduct with different objectives in mind, but that international law mostly (but not entirely) has the tools to resolve any such conflict through the rules of interpretation or through rules of priority. The thesis first establishes that the outbreak of hostilities does not, ipso facto, abrogate the operation of investment treaties. Then, the analysis proceeds to assess the application of investment treaties and their standards of protection in situations of armed conflict. In this respect, the thesis analyzes the legal frameworks that govern the dispossession and destruction of foreign investments, the treatment of investments under the contemporary laws of targeting, and the obligation to protect foreign investments from the effects of armed conflict (precautionary obligation). Having dealt with the substantive standards of protection, the thesis examines whether the occurrence of armed conflicts can be used to exempt, excuse, justify, or carve-out investment obligations during armed conflict. Finally, the analysis deals with the consequences of the State's failure to guarantee the protection of foreign investments as required by international law and the obligation to award 'adequate' compensation for losses owing to armed conflict.