Lawful weapons are better weapons – why I do this work

This article closes the series by answering the question that underpins the first four pieces: why I do this work, and what, in practical terms, I can do for the people who build capability.

The why is straightforward, though it took me years to be able to say it plainly. The law of weapons exists for a blunt reason. War is violent, and the law’s job is not to pretend otherwise but to keep the violence directed: away from the civilian, the wounded and the surrendered, and within limits even where combatants are concerned. I spent my service around the systems that do the directing. I saw what it looks like when a capability does exactly what it should, and I’ve seen the questions that follow when one does not. The people the law protects are real to me in a way no textbook could have managed, and so are the operators, because a crew fielding a system nobody fully understood is carrying a risk that they should not be asked to carry.

That is why the work matters. it is not an abstraction about treaties; it is about what arrives at the other end of an engagement, and who has to live with it.

Alongside that sits a belief that sounds commercial but is really the same belief dressed up differently: lawful weapons are better weapons. A system whose effects are understood, controlled and evidenced is a system a commander can trust, a State can adopt, an ally can accept, and a company can stand behind in public. Nothing about doing the legal work makes a capability weaker or slower. Done at the right time, it is what makes the capability fieldable at all.

This series has made four arguments:

• Legal input belongs at the design table, where the questions are cheap, rather than the final gate, where they are not.
• For autonomous and AI-enabled systems, the review is no longer an event but a relationship that runs for the life of the system.
• Compliance is proved, not asserted, which means trials designed to generate the legal evidence alongside the engineering evidence.
• And the record you build for the State that adopts your system is the same record that protects your company at every rung of the ladder, from the journalist to the courtroom.

Set out together, the four are really one argument: this work is done best early, deliberately, and as part of the engineering, not as a tick-box exercise after it.

So here is what the work actually looks like, stripped of argument.

I join programmes early, at concept and design, and help teams see where the legal questions sit in what they are building: how the system discriminates, how its effects are controlled, what happens at the edges of its intended use, and how a change in the concept of employment changes the answers. I read requirements documents for what they do not say, setting out what a programme will still have to prove even though nobody wrote it down as a requirement. I translate review criteria into evidence plans, and work with test teams so that trials capture the legal proof alongside the performance proof, usually for a modest addition to serials already planned. I help companies build the dossier a reviewing State actually wants: the questions, the evidence against each, the conditions it was gathered in, the chain from raw data to conclusion. For systems that change through life, I help design the architecture of re-review, so that each release carries its evidence with it and the groundwork never stops. I train boards, engineers and capability teams in the law that touches their work, in their language rather than mine. And because things do not always go to plan, I bring experience of investigations and inquiries, having led them as well as advised in them, for companies that find themselves facing the question the last article ended on: what did you know, and what did you do about it?

None of that requires a company to become a law firm, and it does not put a lawyer in the way of the engineering. Most of it is a habit of asking certain questions earlier than the process would otherwise ask them, with someone in the room who knows which questions they are, what the answers need to look like, and what a State on the other side of the table will do with them. I have sat on that other side of the table; it changes how you prepare for it.

The defence sector is being asked to deliver at the pace of relevance, and it is rising to that. My work exists so that the legal side of a programme moves at the same pace as the rest of it: so that the capability that is needed now is also the capability that can be adopted now, exported now, updated now, and defended in public at any point in its life. That is what I spent my service learning to do, and it is what I now do at the Bar.

If you design, build or bring military capability to market, the cheapest moment to involve me is before the questions become expensive, and the second cheapest is today. My door is open, and as of yesterday, it is the only one I keep.

This is the final piece in a short series for defence manufacturers, technology firms and those who bring military capability to market: what the law asks of a system, and how answering those questions early strips risk, cost and delay out of a programme. If any of it touches a programme you are working on, my door is open.