Post-cold war security in international relations is identified as security in the global contemporary. Contemporary global issues are closely related to issues that are no longer dominated by East-West relations, such as the threat of nuclear war, ideological competition between Liberal-Democracy and Marxism-Leninism, crisis diplomacy, and so on. In the perspective of liberalism, peace and security are important for the international system, being considered by international law and organizations. However, recent developments in Afghanistan and Ukraine mark a challenge to this idea and challenge the consistency of peace and security under international law. This study uses a qualitative method by using secondary sources and classifying the data into two, namely security and international law to investigate the situation in Afghanistan. The method of analysis of the Taliban regime in international law uses a juridical-normative approach. The results of the juridical-normative research to describe the situation in Afghanistan are then correlated with the security aspects of the security situation. It is in the case of the new-Taliban state that the situation of the "vacuum" of international law in terms of government recognition can be hijacked to obtain the "approval" of the new regime. The security landscape in the perspective of International Law is fragile against minorities and the vulnerable which can create an unstable international system and encourage the possibility of certain powers to take action to take the opportunity given under the doctrine of effective control. Where must pay attention to aspects of human security, which are related to the obligation to fulfill, respect, and protect human rights recognized in International Human Rights Law. This shows the consistency of actions by member states at the UN, especially big powers like the US and its allies, otherwise similar problems will happen again in the future and weaken the international system as already started in Ukraine.