OnCalls for a single global rulebook are appealing. The idea that every country could follow the same set of rules promises simplicity, certainty and efficiency. The reality is more complicated. One of my more controversial views on regulation is that we should tolerate variation or “interoperability”.

Interoperability is when different systems can work together effectively without having identical rules or structures. In trade, it might mean countries recognising each other’s certifications, aligning data formats, or following shared frameworks that allow for local variation. The goal is to keep goods, services and information moving freely while respecting national differences.

Once basic compatibility between systems is achieved, pushing for deeper harmonisation can cost more than it delivers. Governments protect their sovereignty, NGOs push for utopian frameworks, and businesses simply want predictability and cost control.

In some areas the case for harmonisation is overwhelming. Network effects in digital trade and payments mean that uniform standards deliver far greater value. Systemic risks in aviation safety, pandemic preparedness and financial stability require consistent rules across borders. Occasionally, crises such as pandemics or financial shocks create momentum for deeper integration. But these moments are rare, and the progress they bring can fade quickly unless the agreements are locked into lasting frameworks.

Interoperability offers a practical alternative in most cases. It allows countries to tailor rules to local needs while keeping markets open. It can be achieved faster than full harmonisation and can make systems more resilient by avoiding the risks of a single point of failure. It’s also a more humble and experimental approach: avoiding the hubris of having created “one system to rule them all” and allowing evolution, evaluation, and comparison of different systems.

We already have examples of targeted alignment that work. The WTO Trade Facilitation Agreement streamlined customs processes without overhauling domestic laws. The Extractive Industries Transparency Initiative created a common disclosure framework while allowing national flexibility. The UK Financial Conduct Authority’s fintech sandbox inspired similar schemes overseas. The EU–US agreement on pharmaceutical manufacturing inspections eliminated costly duplication. The Montreal Protocol set binding environmental targets but left countries free to decide how to meet them.

For corporate affairs teams the challenge is to focus on where international stakeholder interests genuinely converge; to engage early in negotiations; to make sure that resulting rules support commercial goals; and to recognise when to stop before overreaching. The most durable progress will often come from agreements that keep trade and cooperation flowing while leaving space for more ambitious steps when the conditions are right.