The study, which examined the regulatory frameworks of eight major European countries – Belgium, France, Germany, Italy, the Netherlands, Spain, Sweden, and the United Kingdom – found systemic obstacles preventing public access to critical information about arms exports and transfers.
“Our research shows that while European nations are signatories to international human rights standards on access to information, significant gaps remain between these commitments and the actual transparency policies and practices in arms trade,” says Asser Institute researcher León Castellanos-Jankiewicz, who supervised the report.
State secrets
Castellanos-Jankiewicz: “Europe exports 30% of the weapons traded worldwide, but suffers from a lack of transparency in this area. State secrets, national security exceptions, and the inability of courts to examine the issue are obstacles that prevent access to crucial information on arms transfers, sometimes with impunity.”
The study analyses domestic legislation, regulations, and judicial decisions in light of international human rights law standards on access to information and international arms control law as benchmarks for evaluating each country's regulatory framework and jurisprudence. It identifies five critical barriers to arms trade transparency across Europe:
- National security trumps public access: A widespread use of national security exceptions block disclosure of information about arms export decisions, deliberations, and oversight processes.
- Fragmented and vague reporting: Federal systems create inconsistent access across regimes within single countries, while government annual reports often lack crucial details about arms exports. Some jurisdictions regulate information access at municipal levels, leading to uneven transparency standards.
- Transparency barriers block justice: Denial of information access prevents affected communities and civil society from building legal cases seeking remedies for human rights violations caused by negligently exported weapons, effectively shielding government decisions from accountability.
- Judicial deference limits oversight: Courts across all eight countries have shown reluctance to challenge executive decisions on arms exports, citing separation of powers doctrines, state secrets laws, and concerns about harming domestic industry. Only rarely have judiciaries held governments accountable for licensing decisions.
- Late and incomplete disclosure: Even where reporting obligations exist, governments frequently publish information late—rendering legal challenges impossible—or provide incomplete data that obscures end-users, exporters, and re-export authorizations, making it difficult to trace weapons supply chains.
Increased defence spending
The findings have significant implications for international efforts to increase accountability in the global arms trade, particularly as states increase defence spending worldwide. Recently, the European Union (EU) unveiled plans in 2025 to spend €800 billion in defense with its ReArm Europe Plan 2030. However, the European arms production and transfers regime lacks comprehensive due diligence and transparency obligations designed to prevent downstream damage, including human rights abuses.
Researcher León Castellanos_Jankiewicz: “Our report clearly shows that the opacity surrounding the European defence sector undermines public oversight and obstructs access to justice for individuals affected by negligent and wrongful weapons transfers. Our report also provides actionable evidence for policymakers and advocates to strengthen transparency mechanisms in the arms trade sector.”
Read the full report
About the report
This research was conducted jointly by the Hague-based Asser Institute for International and European Law and the International Law Clinic of the University of Amsterdam Faculty of Law, bringing together expertise in international law, human rights, and arms control regulation. The study was commissioned by the European Center for Constitutional and Human Rights (ECCHR) in Berlin. ECCHR is an independent, non-profit legal and educational organization dedicated to enforcing civil and human rights worldwide.
The report was written by University of Amsterdam Faculty of Law students Jennifer Bunnik, Ana Gobillon, Jiaxin Li, Jan Melck and Zia Wendt under the supervision of León Castellanos-Jankiewicz. Asser Institute researcher Antonio Guzmán Mutis and research intern Letizia Bozzi provided research and editorial assistance.
