The frequency of terrorist attacks around the world in last decade has repeatedly demonstrated the undeniable danger and deadliness of improvised explosive devices (IEDs), or “homemade” bombs. Over the last 10 years, IEDs have caused at least 171,732 casualties globally.

Many of these casualties occur in conflict regions, such as Afghanistan, Nigeria, or Iraq, where terrorist groups take advantage of weak governance structures, internal conflicts, and grievances to recruit, train and attack. In Iraq, 83 percent of civilian deaths and injuries in the past decade were the result of IEDs. In Afghanistan, where the Taliban are responsible for the majority of IED attacks, they have been the leading cause of conflict-related civilian deaths almost every year since 2001. In Nigeria, ISIS-affiliate Boko Haram carries out most IED attacks, which are responsible for  97 percent of all recorded civilian deaths. In fact, Nigeria has suffered through three of the five most deadly IED attacks globally.

However, IED attacks are not just an imminent threat in conflict areas; these violent tactics employed by terrorist groups have migrated across the globe. Attacks using homemade IEDs in the West date back to as early as 1970 at the University of Wisconsin, which was one of the first major such attacks on U.S. soil. This attack was followed by many similar attacks throughout the United States, including the 1993 World Trade Center Bombing and the 1995 Oklahoma City Bombing. In the United Kingdom and throughout Europe, some of the most notable terrorist attacks carried out using homemade explosives were the 2005 Underground Bombing in London, the 2015 Paris attacks, and the 2016 Brussels attacks. IED dependent attacks have occurred with frequency in other areas of the Middle East, Asia, and Africa, for example, the 2003 British Consulate bombing in Turkey, the 2002 Bali Nightclub bombing in Indonesia that claimed the lives of 202 people, and the 2003 Casablanca bombings in Morocco.

The global prevalence and frequency of IED attacks reflect how they have become the weapon of choice of many violent extremist organizations due to their accessibility. Terrorist organizations have learned how to build homemade bombs from everyday household items and commonly used ingredients, known as precursor chemicals. Some of the most frequently used precursor chemicals are fertilizers such as ammonium nitrate, medications such as potassium chlorate, or bleaching agents such as peroxides.

The frequency of attacks using IEDs also reflects the difficulty of effectively regulating precursor chemicals. Many countries struggle to control the use and distribution of precursor chemicals due to their common and legitimate use in farming, mining, and fireworks manufacturing.

Nevertheless, some countries have created national regulations in an effort to control the distribution and misuse of these chemicals. In Australia, for example, the Council of Australian Governments (COAG) introduced a licensing scheme for security-sensitive ammonium nitrate (SSAN), which contains pure ammonium nitrate (AN). AN is used heavily in agriculture, yet is a common ingredient in homemade explosives. The Australian government regulates the use, manufacturing, storage, transportation, and trade of SSAN above a certain mass. Individuals involved in the supply chain of SSAN must undergo inspections, maintain records, and provide a security plan.  The COAG identified 96 chemicals of concern and enacted a voluntary code of practice for an additional 15 precursor chemicals. The Attorney General’s office then created the National Code of Practice for Chemicals of Security Concern, which took in 2013. Australia has not suffered a major terrorist attack with an IED on its soil since these measures came into effect.

Similarly, the European Union (EU) passed Regulation 98/2013 in 2014, which was updated in 2021. Regulation 2019/1148 bans members of the general public, including economic operators and professionals, from purchasing, owning, or using specific precursor chemicals above certain concentrations without a license. Additionally, Regulation 2019/1148 focuses on the supply chain of precursor chemicals by obligating economic operators to provide appropriate labels, records and, if necessary, report transaction data and verify the identity and license of purchasers. As a direct result of Regulation 2019/1148, the quantity of precursor chemicals available on the EU market has decreased and the threat of misuse has been reduced.

Canada’s Explosives Safety and Security Branch (ESSB) created the Explosives Act, which regulates the handling of explosives and their components. Like the EU’s, Canada’s program requires anyone dealing with explosives and their components to be licensed by the Minister of Natural Resources. Uniquely, Canadians, despite having a license, must apply before selling or manufacturing any product that uses a component restricted under the Explosives Act. The application must contain the personal information of the individual, and information about the location and storage of the restricted component. If the restricted component is AN, the individual must submit a security plan, inform all parties in the supply chain about appropriate security requirements, and record annual inventory reports. If the Explosives Regulatory Division (ERD) finds that the application does not meet the required standard, the application is rejected, and the individual cannot sell or manufacture the restricted component. Canada has charged 21 individuals with offenses related to bomb-making since the Explosives Act went into effect in 2013. Amendments to strengthen the Act are pending.

Globally, the World Customs Organization, in conjunction with the United Nations Office on Drugs and Crime, Interpol, and U.S. Immigration and Customs Enforcement, launched a pilot program in 2010, attempting to test the idea of observing the trade and movements of certain precursor chemicals. Aided by the information readily available online, terrorists are becoming more deadly and the threat of IEDs continues to grow. It is clear that an international approach to the problem is necessary. The World Customs Organization has expressed an interest in transforming the pilot program into a long-term global endeavor to ensure sustainable international cooperation.

With support from the World Customs Organization, the United Nations could initiate an international best-practice, which covers three elements: (i) an extensive list of precursor chemicals like Australia’s policy, (ii) a universal licensing scheme and control over the supply chain like the EU’s policy, and (iii) a production and trade application regime like Canada’s policy. Such an approach will ensure a truly global shield against the growing threat of IEDs by undermining one of the most powerful asymmetric weapons many terrorist organizations use to intimidate and disrupt societies and political structures