Parsing Protectionism and Proliferation

Why intensifying protectionism could make it harder to enforce WMD nonproliferation regimes

https://www.stimson.org/2025/parsing-protectionism-and-proliferation/

The global regime to prevent the proliferation of weapons of mass destruction relies on a complex and interconnected enforcement system coordinated across national and international domains. Volatile tariff policies threaten this delicate balance by increasing the risk that customs authorities miss proliferation threats. Strategic trade control systems must be insulated from the volatility of tariff policy, and interagency coordination must evolve to treat proliferation detection as a core national security function rather than a discretionary add-on.

US Tariffs (Re)Take Center Stage

Over the past several months, U.S. tariff policy has dominated the daily news cycle. Notably absent in this coverage, however, is much discussion about the impact that new tariffs, tariff volatility, and expected accompanying tariff evasion may have on the fragile and still underdeveloped global system of controls against the proliferation of weapons of mass destruction (WMD) and related chemical, biological, nuclear, and radiological material and delivery systems.

The international nonproliferation regime relies heavily on the implementation and enforcement of sanctions and strategic trade controls by national customs and law enforcement authorities. Trade disruptions introduce potential vulnerabilities and risks to the efficacy of that enforcement. Impacts from the previous round of U.S. tariffs in 2018 are difficult to disentangle from the supply chain disruption caused by the global COVID-19 pandemic. And the more significant protectionist measures the United States has adopted or threatened so far in 2025 have introduced destabilizing uncertainty and suggest further restructuring of international trade to come. All of this points to possible future complications in enforcing nonproliferation controls.

Without renewed commitment by the United States and other governments to strengthening the nonproliferation architecture and national enforcement capacity, a new era of increasing and volatile trade barriers could become an attractive free-for-all for proliferators and their associates.

Strategic Trade Controls for WMD Nonproliferation

A signature quartet of legal instruments—the Biological Weapons Convention (BWC), the Chemical Weapons Convention (CWC), Nuclear Non-proliferation Treaty (NPT), and the overarching UN Security Council Resolution 1540 on nonproliferation—embody the global WMD nonproliferation architecture. A commonality among the four is the political commitment signatory states make not to transfer or help others acquire such weapons. The effectiveness of these frameworks relies heavily on national implementation and enforcement of strategic trade controls, including export controls and sanctions. While countries have achieved varying levels of implementation of these obligations, customs authorities play a critical frontline role in recognizing proliferation red flags, detecting suspicious activity, and enforcing compliance by screening imports and exports for anomalies, inspecting shipments, and reviewing documentation.

Looking for a “Needle in a Haystack”

The task of these customs frontline officers has been described as looking for the proverbial “needle in a haystack.” Many of the items subject to the strategic trade controls that customs are responsible for enforcing have legitimate and beneficial agricultural, medical, industrial, and even household uses, as well as potential applications for biological, chemical, or nuclear weapons development. These so-called “dual-use” items can be difficult to identify under the best of circumstances. Yet customs must do this while screening and processing massive volumes of goods crossing borders, balancing small package e-commerce with traditional containerized shipments, and monitoring and enforcing compliance with numerous other international commitments and national laws controlling or prohibiting international trade in narcotics, wildlife, counterfeit goods, human beings, and more. All these obligations exist in addition to the job of calculating and collecting duties and tariffs owed on goods.

Meanwhile, evaders of sanctions, export controls, and tariffs work hard to outwit the authorities. Methods used by Iraq in the 1990s to build its WMD programs; by Iran, whose nominally peaceful nuclear activities are an international proliferation concern; and by North Korea to circumvent international sanctions and export controls are well documented. And while tariff evasion cannot be observed and measured directly, experts cite ample anecdotal evidence, and studies have found relationships between trade discrepancies and tariff levels that provide further support for the supposition. U.S. importers are already reporting a rise in tariff-related trade fraud since the imposition of tariffs on Chinese goods. These effects will likely not be limited to the United States since many countries are retaliating with their own new tariffs on U.S. goods.

Of Haystacks and High Tariffs

An environment of punitive tariffs and uncertainty has several potential implications for the WMD nonproliferation regime. The first is related to the expected rise in tariff evasion and the commonalities between proliferators and tariff evaders. In both cases, the actors are working largely with goods that can flow legally for commercial purposes. They also use similar tactics to evade authorities. Proliferators’ use of mislabeling, transshipment via third countries, and front companies have similarities with contemporary tariff avoidance behaviors. As evasive trade practices, obfuscation, and fraud become more prevalent, the size of the “haystack” that customs must search for illicit transactions becomes progressively bigger.

More—and more volatile—tariffs worldwide could also affect the workload prioritization and organization of customs authorities. The International Monetary Fund (IMF) identifies the protectionist environment since 2018 as part of broader structural changes affecting the global economy that could result in heavier customs workloads and an even more complex regulatory environment. This situation, with tariff levels changing sometimes day by day, will serve to further distort and disrupt established trade patterns and relationships and undermine efforts to detect the anomalies that can help identify a proliferation risk. Related to this, disruption to supply chains makes it easier for actors with nefarious intent to exploit newer, less secure, or less-well-vetted vendors for their own purposes. This strategic trade control vulnerability also emerged during the supply chain disruptions caused by the COVID-19 pandemic.

Finally, the international nonproliferation framework, like customs-centric efforts to counter other transboundary threats, relies on international cooperation and partnership. The legally binding commitments assumed by signatories to the BWC, CWC, and NPT are broad and high-level, supported primarily by subsequent voluntary undertakings made by smaller groupings of states to harmonize their export controls and share information on licensing. Even the security and trade control obligations assigned to all member states by UN Security Council Resolution 1540 rely on cooperation between willing governments and multilateral organizations to share best practices for eventual full implementation. Yet protectionist trade policies undermine this cooperation by focusing the attention of otherwise like-minded governments on managing trade disputes rather than coordinating on common challenges.

Avoiding a Strategic Blind Spot

The re-emergence of protectionist trade policies poses more than just economic consequences; it threatens to erode the architecture of global nonproliferation. Customs authorities, already tasked with an expanding portfolio, cannot be expected to detect proliferation risks if they are overwhelmed by tariff-driven enforcement priorities. Governments must recognize that trade measures and security objectives are not mutually exclusive areas. Strategic trade control systems must be insulated from the volatility of tariff enforcement, and interagency coordination must evolve to treat proliferation detection as a core national security function rather than a discretionary add-on. Failing to align these policy domains risks turning legitimate trade disruption into a proliferation opportunity.