More attention is needed on how international criminal law applies to cyber operations. This Chatham House research paper follows a new policy issued by the Office of the Prosecutor of the International Criminal Court. Both seek to fill that gap.
As society’s dependence on information and communication technologies (ICTs) grows, so does its vulnerability to attack. Recent examples include the Russian army using cyber capabilities to shut down power grids in Ukraine, state-sponsored hackers infiltrating water supplies, and the hacking of nuclear sites.
There is a risk of impunity for those using the most harmful forms of cyber activity. States have consistently affirmed that existing international law, including the UN Charter, applies to the cyber activities of states. But, until recently, little attention has been paid to whether individuals who inflict serious harm by cyber means can be held responsible under international criminal law and, if so, how.
Many national laws already cover ‘cybercrimes’ such as online fraud, theft or hacking. But there are some circumstances in which the nature and severity of cyber operations place them in an additional category – that of an international crime. It is notable that, of the states that have published position statements so far on the application of international law to cyberspace (over 100, factoring in regional position statements), only one – Austria – has so far referred to international criminal law.
While it has become evident that no new law is required to capture the core international crimes when carried out by cyber means, further attention is needed as to the way in which the existing law applies to the circumstances of cyber operations. There is also a need to confront the particular challenges that arise when the perpetrators of cyber-enabled international crimes are brought to justice. While the difficulties should not be underestimated, the existence of an effective framework for investigation and prosecution of such crimes may help to prevent them.
About this paper
In 2024 and 2025, Chatham House’s International Law Programme hosted expert roundtable discussions, held under the Chatham House Rule, on the strengthening of accountability for cyber-enabled international crimes. These discussions were attended by government legal advisers and prosecution authorities, officers from the ICC, representatives from technology companies, and leading academic experts in the fields of international humanitarian law and international criminal law. The International Law Programme also conducted desk research, literature reviews and interviews with experts. This paper draws on insights from each of these sources.
The objectives of the paper are:
- To clarify which cyber activities come within the range of international criminal law (Chapter 2);
- To consider the legal framework for securing justice effectively (Chapter 3);
- To discuss the opportunities and challenges involved in pursuing accountability for committing international crimes; and to consider how the challenges might be addressed, including how to promote effective partnerships between courts, states and the private sector (Chapter 4); and
- To make recommendations on how to strengthen avenues for accountability in this area (Chapter 5).
In this paper, the term ‘cyber’ refers not just to traditional cyber technologies (such as those used in ransomware or hacking operations), but also to digital technologies more broadly (including social media networks and the internet). The term ‘cyber-enabled international crimes’ refers to genocide, crimes against humanity, war crimes and aggression committed or facilitated by cyber means. ‘Cybercrimes’, on the other hand, are defined in international treaties as including online fraud, theft or hacking. They do not fall in the category of core international crimes as such, though it is possible for a cyber operation to constitute both a cybercrime and an international crime.
This research paper brings the OTP’s policy to a wider audience, expands on certain issues arising from that policy and proposes solutions to some of the challenges in the field. Our paper also widens the discussion to explore the role of national courts, as it should ordinarily fall on them to prosecute, where possible, cyber-enabled international crimes. Though its main object is to explain the ICC’s prosecution policy, the OTP paper is likely in addition to be a useful guide to all countries on their own investigation and prosecution of international crimes.
