The present article aims to analyze the repercussions that both international terrorism and the forceful responses against terrorist threats have had in the current world order; in particular their implications on civil population (with emphasis on the situation of the internally displaced persons and refugees). Thus, this work begins with a brief analysis of contemporary international terrorism and the antiterrorist fight, with a view to determine the legality or illegality of forceful responses against terrorism under relevant international law in force (with special emphasis on the ius ad bellum). Next, the article addresses the consequences of the use of armed force against terrorism on civil population (i.e. International Law of Human Rights and International Humanitarian Law —ius ad bellum—, specifically on the internally displaced persons and refugees. Finally, and assessment is made concerning the adequacy or failure of contemporary international law under the United Nations legal system (i.e. use of armed force, Human Rights, International Humanitarian Law, and the legal framework of the refugees and the internally displaced persons) to deal with the current situation which is object of this article. It is worth noting that the present work assumes that the branches of international law under analysis represent different dimensions closely linked with the same phenomenon. Therefore, it is understood that the study of any of these aspects must be carried out in close connection with the others. To conclude, it should be noted that the analysis comprises only the coercive responses (i.e. the use of armed force) of State and the international community against terrorist activities. Hence, the consequences of the peaceful responses against international terrorism on the internally displaced persons and refugees are not within the scope of this article. [ABSTRACT FROM AUTHOR]