Speed, Power and Restraint: Why Article 36 Legal Reviews Matter More Than Ever
Recent global events demonstrate that international law is under pressure (here, here, here). They expose deep tensions within the UN framework designed to maintain global order, legality and accountability in the international system. As a consequence, States are rearming at an increasing pace, investing heavily in new military capabilities while actively seeking to reduce what are perceived as bureaucratic impediments to rapid capability development and deployment.
In this environment, established international humanitarian law (IHL) practices such as Article 36 legal reviews may be characterised as slow, idealistic or ill-suited to modern weapon acquisition requirements.
Are national legal reviews of new weapons under Article 36 of Additional Protocol I a peacetime luxury, important in theory, but expendable in practice when speed and national survival are at stake? This blog argues that this framing is not only legally flawed but is strategically short-sighted.
Armament at Speed
Global military expenditure continues to rise sharply. Recent reporting by the Stockholm International Peace Research Institute (SIPRI) confirms that States are spending at historically high levels, driven by major-power competition, regional instability and the perceived lessons of contemporary conflicts. Procurement cycles are shortening, acquisition pathways are being streamlined, and emphasis is increasingly placed on speed, adaptability and “minimum viable capability”.
Nowhere is this trend more evident than in relation to artificial intelligence (AI) and autonomous systems. These technologies promise operational advantage through rapid data processing, decision-support and, in some cases, the delegation of functions traditionally performed by humans. They are also being developed in a policy environment that is often sceptical of legal review processes.
The risk is clear: legal review obligations come to be seen as friction, something to be minimised, deferred or absorbed into generic compliance processes rather than treated as a substantive requirement of international law.
An Old Rule for New Technology
Yet the legal baseline could not be clearer, nor more enduring. The the Hague Peace Conferences of 1899 and 1907, and more recently in Additional Protocol I, States have historically recognised a foundational rule of the law of armed conflict:
In any armed conflict, the right of the Parties to the conflict to choose methods or means of warfare is not unlimited.
This principle remains at the core of IHL and is operationalised through Article 36 of Additional Protocol I.
Article 36 does not prescribe a particular institutional model or procedural template. It imposes an obligation of result: States must determine whether a new weapon, means or method of warfare would be prohibited by international law in some or all circumstances. That determination must be genuine, informed and made before the capability is fielded in armed conflict.
If anything, the rationale for this obligation is stronger today than it was 125 years ago. AI-enabled and autonomous systems are complex, adaptive and often opaque. They raise difficult questions about predictability, reliability, human control, accountability and escalation, precisely the kinds of issues that legal review is designed to surface early, before they crystallise into operational or strategic risk.
Ukraine and Legal Review Under Fire
The experience of Ukraine provides a compelling example of why legal review matters most when it appears hardest to do.
Prior to Russia’s illegal invasion in 2022, Ukraine did not have a formal national Article 36 legal review process. Like many States, it faced competing priorities and limited resources. Yet, in 2024, even during an ongoing armed conflict, the Ukrainian Ministry of Defence recognised the necessity of establishing national legal review practices and developing national capacity.
This decision is significant. It demonstrates that legal review is not a peacetime luxury detached from battlefield realities. Rather, it is an operational safeguard, a mechanism for ensuring that military necessity is exercised within lawful bounds, and that new capabilities do not introduce unforeseen legal, political or alliance-level consequences.
Ukraine’s experience directly challenges the assumption that speed and legality are mutually exclusive. It shows that even under extreme pressure, States can treat legal review as an essential component of responsible defence capability development.
The False Economy of Cutting Corners
There is an understandable temptation to cut legal and ethical corners in the pursuit of rapid capability. In the short term, doing so may appear to offer speed and flexibility. In the longer term, it often creates exactly the opposite.
Capabilities developed or deployed without robust legal review may later be restricted, withdrawn or politically contested. They can expose States to international responsibility, undermine interoperability with allies, and erode domestic and international trust. For private-sector developers, inadequate legal scrutiny can lead to stranded investments, reputational harm and exclusion from future procurement programmes as regulatory and political expectations catch up.
More broadly, the cumulative effect of States treating legal review as optional weakens shared legal baselines and fragments State practice. At a time when international law is already under strain, this erosion is particularly dangerous.
Lawful by Design: From Constraint to Capability
This is precisely the gap that the Lawful by Design initiative seeks to address. Lawful by Design starts from a simple but often overlooked premise: compliance with international law should not be retrofitted after a capability is built, deployed or publicly contested. It should be embedded from the earliest stages of design, development and acquisition.
Rather than treating Article 36 legal review as a final gate or bureaucratic hurdle, Lawful by Design reframes it as a continuous, life-cycle-oriented process. Legal considerations inform system requirements, human-machine interface design, concepts of use, testing and validation, and ultimately deployment and modification decisions. In this way, legal review becomes an enabler of speed and agility, reducing downstream risk, uncertainty and delay.
In an era of AI-enabled and autonomous weapons, this shift is critical. Early legal engagement supports better engineering choices, clearer operational boundaries and more defensible procurement decisions. It also provides States and industry with a shared language for addressing legal risk before it becomes a political or strategic liability.
Conclusion
The current security environment does not justify weakening Article 36 legal review obligations. On the contrary, it demands renewed investment in them, alongside approaches, such as Lawful by Design, that integrate legal review into modern defence innovation rather than treating it as an obstacle.
The principle recognised at The Hague over a century ago remains as relevant today as it was then: the choice of means and methods of warfare is not unlimited. In an era of accelerating military innovation, Article 36 legal review remains one of the few tools States possess to ensure that power is exercised with restraint, foresight and legality.
The real question is not whether States can afford robust legal review processes — but whether they can afford the consequences of neglecting them.
