How might 'novel effector' technologies impact strategic stability?

A raft of ‘novel effector’ technologies are maturing at pace. Some, such as hypersonic missiles, are already in operational use. Others, such as Directed Energy Weapons (DEWs) are on the cusp of more regular deployment. The landscape for these technologies is fast moving, and accelerating, but the strategic implications of these technologies are poorly understood. This impacts international governance and stability, and the UK’s relative positioning in these technologies.

This project, commissioned by the UK Foreign Commonwealth and Development Office (FCDO), explores the strategic stability implications of so-called ‘novel effector’ technologies in the defence context. It defines the novel effector technologies of most strategic concern and charts their development trajectories across major actors. Using a strategic cultures lens of analysis, it then considers relative perceptions of their use across major actors before considering options for their international governance based on the most pressing gaps and risks, before assessing opportunities for the UK.

Novel effector technologies are complex to categorise and have varied implications, but they three strategic implications. Focusing on hypersonics, directed energy weapons, cyber, autonomous and electromagnetic pulse, we identified three core common characteristics. Each of these technologies can compress decision-making timescales, reduce attributability and proliferate widely. These risks are heightened by divergent assumptions among major actors how such may be used. In some contexts, non-nuclear systems could also be perceived as threatening nuclear command and control, creating escalation risks.

Prospects for binding international governance in these technologies are found to be limited, given low convergence between major actors on the technologies’ intended uses and acceptable constraints. However, targeted transparency and confidence-building measures could help manage the most acute risks: miscalculation and inadvertent escalation for hypersonics and DEWs; ambiguity over civilian infrastructure, legitimate targets; and human oversight for autonomous, cyber and electromagnetic effectors.

The UK also has competitive opportunities in this technology space. The UK’s defence research and development (R&D) base and strengths in DEWs and selected hypersonic sub-systems create scope for targeted leadership. A selective approach would prioritise sovereign ownership where essential, collaboration with allies where advantageous, and assured access to fast-moving innovations where partnership is the most efficient route.

Based on our research, the UK Government should prioritise the following actions:

The FCDO and Ministry of Defence (MOD) should seek to avoid misunderstanding and miscalculation around novel effectors, by seeking broad international alignment on the categorisation of novel effectors and their use cases. The UK should focus efforts on capturing the approaches of adversaries and ensuring that these are also considered when assessing the strategic, operational and tactical implications of novel effectors. These efforts should focus on managing inadvertent escalation risks through mutual miscalculation.

The FCDO should note that binding ‘hard’ governance mechanisms around most novel effectors are not likely to be plausible. Accordingly, the UK, led by the FCDO and MOD, should seek consensus among allies and partners on the international governance of novel effectors through targeted channels. The MOD, in parallel, can lead on the institutionalisation of military-to-military communications, demonstrating best practice through forums such as AUKUS. This could enable the UK to secure a first mover advantage in global norm setting around novel effectors, creating precedent for the use case of these technologies, enhancing the likelihood of success for confidence building measures

In parallel and finally, the UK should leverage its defence-industrial strength and competitive advantage in the technology set assessed. The MOD should lead on ensuring that the UK takes a targeted approach towards the development of novel effectors by leveraging existing defence-industrial strengths to derive economic growth opportunities in areas where it can capitalise on niche expertise and structural strengths (in DEWs and sub-systems level in hypersonics). HM Treasury can support this by focusing grant funding and early-stage development contracts accordingly. This parallel approach could bolster the likelihood of success in governance dialogues, as the UK establishes a position of credibility in relation to the technologies.

29 Sep 2026 Novel effectors: Implications for strategic stability of hypersonics, directed-energy weapons, cyber, electromagnetic and autonomous effectors This project examines how maturing novel effectors, including hypersonics, directed energy, cyber, electromagnetic and autonomous systems, affect strategic stability, international governance and the United Kingdom's strategic position. Stuart Dee, Mattias Eken, Zsofia Wolford, Sarah Winder, Conlan Ellis, Harper Fine, Clara Le Gargasson, Evie Graham, James Black

Novel effectors: Implications for strategic stability of hypersonics, directed-energy weapons, cyber, electromagnetic and autonomous effectors

This project examines how maturing novel effectors, including hypersonics, directed energy, cyber, electromagnetic and autonomous systems, affect strategic stability, international governance and the United Kingdom's strategic position.

Stuart Dee, Mattias Eken, Zsofia Wolford, Sarah Winder, Conlan Ellis, Harper Fine, Clara Le Gargasson, Evie Graham, James Black

Stuart Dee RAND Europe Research Leader - Defence Economics & Acquisition

RAND Europe Research Leader - Defence Economics & Acquisition

Mattias Eken Senior Analyst

Zsofia Wolford Senior Analyst

Katie Passey Project Manager