Thanks to its regulatory powers, robust digital economy, and active foreign and security policy, the European Union is one of the key players in cyberspace. The EU strongly promotes the position that international law, and in particular the United Nations (UN) Charter, applies in cyberspace. As a complement to binding international law, the EU endorses the voluntary non-binding norms, rules and principles of responsible State behaviour that have been articulated by the UN Group of Governmental Experts. It also encourages the development and implementation of regional confidence building measures, both in the Organisation for Security and Co-operation in Europe and other regions. On a bilateral level, the EU has established cyber dialogues with strategic partners to reinforce the exchange of good practices, lessons learnt and further the idea of responsible state behaviour in cyberspace.

The United Kingdom ranks 10^th in the 2021 Network Readiness Index (NRI), 9^th in the 2021 Digital Skills Gap Index and 14^th in the 2021 IMD World Digital Competitiveness Ranking. The British digital sector contributes roughly £149 billion each year to the economy and employs more than 1.5 million people [x]. The country also remains Europe’s unofficial ‘start-up capital’, with British tech startups attracting more than $15 billion in venture capital investment in the midst of a global pandemic. Nevertheless, new and emerging challenges to peace and security in cyberspace represent pressing concerns for the UK [x]. Over the course of 2021, the UK’s National Cyber Security Centre dealt with 777 significant incidents, with around 20% of supported organisations being linked to the health sector and Covid vaccines [x]. In the face of ever-increasing cyber vulnerabilities, the UK government has recently adopted a strategy of ‘levelling up’ protection for British cyberspace. This has brought international collaboration on cyber issues to the forefront of Britain’s diplomatic agenda. British diplomacy has traditionally championed the rules-based international system both online and offline, placing great emphasis on human rights, democratic values and free trade.

The United States has historically been a strong partner in cyber diplomacy for the EU based on common values (human rights, rule of law), goals (open, stable and secure cyberspace) and interpretation of international law. Cyber diplomacy with the US has also been operationalised in the form of information-sharing and cooperation to tackle cybercrime, cooperation on cyber defence via NATO and cyber capacity building in third countries. Despite differences over certain foreign policy issues, the EU and the US remain close allies in cyberspace.

Under the auspices of the UN, the EU and its Member States have consistently reaffirmed that a universal cyber security framework can only be grounded in existing international law, including the Charter of the United Nations in its entirety, international humanitarian law, and international human rights law. 
Addressing issues as to how existing international law and international humanitarian law, including the principles of humanity, necessity, proportionality and distinction, apply to the use ICTs by States is necessary to increase accountability and transparency. International humanitarian law is fully applicable in cyberspace and this should not be misunderstood as legitimising the use of force between states in the cyber domain. The EU has typically opposed calls for the need to adapt existing international law as a means to develop a new legal instrument for cyber issues.

The UK views international law as “a critical tool for ensuring stability and security in cyberspace”. In accordance with the 2013, 2015 and 2021 UNGGE reports as well the 2021 OEWG report, the UK has affirmed that international law, including the UN Charter in its entirety, applies in cyberspace; a position paper notably states that “we do not consider it is for States to pick and choose which international law instruments are applicable”. This includes the prohibition of the use of force (Article 2(4)), the peaceful settlement of disputes (Article 33) and the inherent right of states to act in self-defence in response to an armed attack (Article 51). The law of state responsibility applies to cyber operations in peacetime, including the doctrine of countermeasures in response to internationally wrongful acts. Meanwhile, the country has professed a strong commitment to the respect of human rights law in cyberspace, co-sponsoring the 2012, 2014, 2016, 2018 and 2021 UN Human Rights Council resolutions on the protection, promotion and enjoyment of human rights on the Internet. Likewise, the UK believes in the application of international humanitarian law (IHL) to cyber operations in armed conflict. In response to concerns expressed by other states that this might lead to an undue ‘militarisation’ of cyberspace, the UK has responded that the application of IHL does not encourage armed conflict but only serves to limit humanitarian consequences in the event of such conflict. In addition, the country has stated and that there are ways for cyber capabilities to be developed in a manner “consistent with international law” and called on states to be transparent about the existence of their own capabilities. Those statements do not entirely dismiss the idea of cyberspace as a new military domain, with the British position at the OEWG being that “the use of ICTs in military contexts may be preferable to use of kinetic weapons and can be de-escalatory”. The UK is against the establishment of new, binding international instruments to regulate state behaviour in cyberspace, arguing that “pursuing […] the development of new treaties is only likely to entrench existing divides in this area and will progress us no further on the question of how International Law applies”.

The US believes that international law is applicable in cyberspace. As part of the ‘like-minded’ coalition, the US recognises a need to acknowledge the full breadth of relevant international law, including international humanitarian law (IHL), human rights law, customary international law on the responsibilities of states for internationally wrongful acts. The general applicability of IHL in cyberspace is not to be misconstrued as a tacit endorsement of aggression in the cyber domain; instead, it only serves to remind states of the responsibility to respect and protect civilians in the event of armed conflict. 
In the context of multilateral fora, US diplomats have specifically emphasised the applicability of the right to self-defence under Art. 51 of the UN Charter, noting that a State may lawfully take cyber-based or non-cyber-based countermeasures in response to internationally wrongful cyber activities attributable to another State, but only subject to the requirements of the doctrine under international law and the principles of necessity and proportionality.

Since 2014, the EU’s ambition has been to act as an ‘honest broker’ on multilateral discussions surrounding issues of cyber governance and norms of responsible state behaviour, aiming to ensure the support and partnership of proactive players in the context of the global debate. The EU has long promoted the need for voluntary, non-binding norms. It believes that norms crystallised under the UN GGE process should generally not be revisited and that progress should be made on matters relating to their implementation. 
Within the OEWG, the EU advanced a suggestion to develop a global repository of existing practice within the United Nations, which would enable UN member states to showcase how they are implementing the voluntary norms of responsible state behaviour, confidence building and other measures.

The UK regards voluntary, non-binding norms of responsible state behaviour as one of the three key pillars upon which the framework for international stability in cyberspace is currently built, the other two being international law and confidence-building measures (CBMs). The British have argued that “stronger awareness and understanding by all countries of the framework in general” is necessary and stated that they “remain concerned that the elaboration of new norms could undermine the existing norms by weakening the overarching protection they provide, or their technology neutral and ‘future-proofed’ nature”. The focus should instead be on the universalisation, operationalisation and implementation of existing norms, with regional organisations and capacity-building efforts playing a central role in this endeavour.

As stated in the 2018 National Security Strategy, the United States views voluntary, non-binding norms of state behaviour during peacetime as essential components of a framework of responsible State behaviour in cyberspace. The US has participated in all iterations of the UN Group of Governmental Experts (UNGGE) as well as the latest Open-Ended Working Group.
In these multilateral fora, US diplomats have typically opposed attempts at shifting to a legally binding status for norms of responsible state behaviour, arguing that such discussions are “premature” and do not represent the best way to address the immediate threats given the fast pace of technological developments. 
The starting basis for any further discussions on the part of the US rests on the current buildup of consensus surrounding the norms identified in the 2015 and 2021 GGE reports. Efforts should be concentrated on the implementation of existing consensus norms, not the creation of entirely new normative concepts (i.e. in relation to harmful hidden functions and specific critical infrastructure sectors).

The EU places great importance on cyber resilience and capacity building. Internally, the Union has built a robust legal acquis in relation to the resilience of critical infrastructures, the cornerstone of which rests upon the 2016 Network and Information Security (NIS) Directive and the 2013 and 2019 Cybersecurity Acts. This legal meshwork seeks to integrate cybersecurity into all elements of the supply chain and introduce soft law mechanisms like the EU cybersecurity certification scheme. In doing so, it harmonises national cybersecurity capabilities, cross-border collaboration and the supervision of critical sectors across the EU. 
In the coming months, the Commission intends to add upon the existing cyber-acquis by introducing an array of new initiatives, such as the updated NIS Directive (the so-called NIS2), a proposal on a Critical Entities Resilience (CER) Directive, and a plan to launch a network of Security Operations Centres across the Union. The aim is to create a Union-wide ‘cybersecurity shield’ that will facilitate the detection of cyberattacks and provide an impetus for proactive action. 
This internal buildup of capabilities is supplemented by the development of a specialised ‘cyber diplomacy toolbox’ that allows the Union and its Member States to address cyber incidents through various joint policies, from cooperation and stabilisation measures to restrictive measures and attribution.

The July 2021 policy paper on Global Britain in a Competitive Age makes extensive reference to resilience in the post-Covid ICT environment, pledging that the UK will “strengthen global resilience” and “ensur[e] that more resilient countries worldwide can come together through stronger international institutions to act on the most pressing shared challenges”. In the cyber domain, this pledge has been further operationalised by the 2022 National Cyber Strategy, which frames cyber resilience in terms of risk awareness, system security and preparedness. The Strategy prioritises capacity building, adopting a whole-of-government approach and focusing on three elements: protecting critical international supply chains and infrastructure, advancing the secure use of digital technologies and working with industry partners and academia. Since 2016, the UK has worked through the National Cyber Security Centre (NCSC) to adopt an integrated approach to cyber incident management, streamlining across the public and private sectors. Meanwhile, Britain has championed
capacity-building assistance efforts abroad by providing advice, training and exercises and enabling the creation and maintenance of national Computer Security Incident Response Teams (CSIRTs). It has also provided funding to international capacity-building platforms, such as the Forum of Incident Response & Security Teams (FIRST) and the Americas CSIRT network. The UK has been working with partners within the OSCE to encourage the implementation of confidence-building measures (CBMs).

The March 2021 Interim National Security Strategic Guidance states that “[the US] will make cybersecurity a top priority, strengthening our capability, readiness, and resilience in cyberspace.” Following the recommendations of the 2020 Solarium Commission, the US government has adopted the concept of ‘layered resilience’ and is gradually rolling out a comprehensive arsenal of resilience measures across a variety of domains. 
The US has been active in engaging in strategically-minded capacity building with partners; US capacity building in Africa with organisations such as the African Union and SADC, for instance, have been largely motivated by Washington’s wish to promote an open, secure, and democratic model for Internet governance across the African continent. 
In relation to cyber defence, there have been several joint operations and military exercises, both bilaterally (e.g. between the US Cyber Command and the Montenegrin military) and under the auspices of NATO. Recent regional engagement efforts such as the dialogues in the context of the tripartite AUKUS coalition and the Structured Quadrilateral Security Dialogue (the eponymous Quad) also heavily feature references to collaborative cyber-capacity building. In multilateral fora, the US has also welcomed the inclusion of confidence-building measures in the GGE reports and noted that, in order for CBMs to be useful, they need to be implemented at minimum on a bilateral basis and preferably on a multilateral and eventually an international basis.

The EU has been an early champion of the Budapest Convention signed under the auspices of the Council of Europe, given the overlapping membership of the two organisations. Much of the EU’s cyber diplomatic efforts have focused on promoting the Convention as the main instrument of choice for fighting cybercrime on a global level. EU member states have consistently opposed Russian bids for replacing this regime with another legal framework. 
The Union is represented in the recently constituted Ad Hoc Committee established by UNGA resolution 74/247 by its Member States and is currently focused on ensuring that the process is inclusive, transparent, consistent with the progress of the UNGGE and OEWG processes, and committed to legal consistency.

According to the 2022 National Cyber Strategy, the UK is committed to promoting the Council of Europe’s Budapest Convention on cybercrime as the primary international instrument for inter-state cooperation, while simultaneously engaging constructively with the UN process to develop a new international cybercrime treaty that will sit comfortably alongside the Budapest regime. In terms of law enforcement, the UK has developed well established mechanisms through the National Cyber Crime Unit (NCCU), operating under the umbrella of the National Crime Agency (NCA). The NCCU is tasked with leading the operational response, coordinating activity across different stakeholders and providing specialist cyber support across the law enforcement domain. The NCA has also developed a network of international liaison officers, which regularly cooperate with Interpol and Europol. Bilateral cooperation with international partners occurs on the basis of the Budapest Convention and associated Mutual Legal Assistance Treaties (MLATs), which facilitate information sharing amongst signatory states. The UK has been an active participant – and has provided voluntary contributions – in the context of discussions for developing a Second Additional Protocol to the Convention to enhance the speed and efficiency of international evidence sharing; the Protocol will be opened for signature in May 2022. The UK has also provided capacity-building assistance to over 100 partner countries, especially in Eastern Europe, Southeast Asia and Africa.

The US is a signatory and an early proponent of the Budapest Convention. A big part of American cyber diplomatic activity has, in fact, been focused on promoting the Budapest regime as the global model of cybercrime governance. In 2019, the US firmly opposed the Russian-sponsored resolution calling for an alternative legal instrument to the Convention; following the passing of the resolution, however, the US has agreed to participate in the Ad Hoc Committee established under UNGA resolution 74/247 despite the fact that the “surprise text” within the May 2021 resolution was seen as an effort to “circumvent dialogue” and undermine the “balanced, inclusive, consensus-based process” sought by the US. 
On a multilateral level, the US is also a party to the UN Convention against Transnational Organised Crime (UNTOC) and the Inter-American Convention on Mutual Legal Assistance of the Organisation of American States (OAS) and is a member of Interpol. 
Bilaterally, the US has completed an agreement with the UK under the CLOUD Act that facilitates cross-border data sharing directly between US companies and the British government; the US is trying to expand this type of bilateral engagement, currently negotiating a similar agreement with Australia.