Increasing dependence on nuclear energy for security, commercial and domestic purposes has enhanced the possibility of nuclear terrorism. It is a general perception that nuclear weapon and weapon-related material, technology and infrastructure could be misused by terrorist groups for nuclear terrorism to achieve their objectives. Presently, a new wave of terrorism in Europe and Asia, especially the increasing the threat of Islamic State (ISIS), has added the risk of nuclear attack. Due to inadequate security measures, nuclear programs for the peaceful purpose are equally vulnerable to terrorists. These scenarios suggest that increasing threat of terrorist groups and influence of non-state actors has destabilised the global safety and security arrangements regarding nuclear terrorism. Contemporary situation grants that dealing with nuclear terrorism is a cumbersome task and viewed as a challenging threat to world peace. That is why the issue of nuclear terrorism has received special attention of the international community during the International Conference of IAEA on Nuclear Security: Commitment and Actions. During the conference, IAEA chief Yukiya Amano stated that: “Terrorists and criminals will try to exploit any vulnerability in the global nuclear security system. Any country, in any part of the world, could find itself used as a transit point. And any country could become the target of an attack.” This statement illustrates the global concerns regarding nuclear security and threats. However, to counter the nuclear threat, it is significant to remember that nuclear threats and challenges are continuously evolving. And it is imperative to identify the sources and instruments of the issue to classify the measures to eliminate the chances of nuclear terrorism, trafficking of nuclear materials and to ensure the protection of nuclear-related facilities and materials. Nuclear terrorism is characterised by numerous techniques in which terrorist groups could use nuclear material and infrastructure. It is vital to understand that nuclear terrorism has many forms and each form of nuclear terrorism has its own degree of consequences. In this regard, four significant scenarios have been identified by the IAEA regarding nuclear terrorism, which include stealing or buying of the nuclear arsenal by terrorist groups from the black market, attack on nuclear facilities to achieve political objectives, manufacturing of nuclear weapon or Radiological Dispersal Device. Though building a nuclear weapon by terrorist groups is the least likely scenario because fissile material is required to manufacture nuclear arsenal and obtaining fissile material is very difficult. On the other hand, it is very easy for terrorist groups to develop a dirty bomb or Radiological Dispersal Device. Low-level nuclear waste including the by-product of nuclear power generations and medical debris waste have the ability to affect health and cause serious biological disorders. Additionally, dispersion of harmful radioactive materials through conventional explosives will be disastrous. These scenarios present that misperceptions, ignorance and miscalculation has made nuclear terrorism a viable threat to international peace and security. In this regard, IAEA’s safety and security strategy is comprised of three substantial pillars including prevention, detection and response. Firstly, IAEA aims to prevent non-peaceful use and trafficking of nuclear-related material, infrastructure and equipment through physical protection. In this regard, IAEA has been conducting training workshops and advisory service missions for the physical protection of nuclear-related equipment to ensure nuclear security. Secondly, to ensure detection, significant efforts has been made to identify the patterns of illicit trafficking of nuclear or radioactive materials. Third, to respond quickly to a nuclear attack, IAEA is working with national, international and regional states. IAEA and member states have also hosted workshops to explore how collective measures should be taken to ensure security against sabotage or nuclear attack. Dual use of nuclear power and emerging sophisticated terrorist groups (ISIS, Al-Qaeda) has made the chances of nuclear terrorism a bitter reality, besides, ignoring the threat of nuclear terrorism under these scenarios will be the biggest gap in the state’s policy choices. Nuclear terrorism, being a universal threat, demands national and international governing mechanism and collective practical measures to deal with the its risk, regardless of state boundaries, by involving all the stakeholders. The threat requires robust international cooperation, assistance and regional measures to counter the social, economic, political and security consequences because there is no defence against the nuclear offence. The writer is Research Associate at Strategic Vision Institute, a think-tank based in Islamabad. Email:asmaakhalid_90@hotmail.com