Necessity? Not Necessarily.

Overnight, the House of Commons passed the Northern Ireland Protocol Bill, and so triggered an unusual debate on an obscure point of public international law – the defence of “necessity”.

Some background. One of the many complications that arose when the United Kingdom voted to leave the European Union in 2016 was the problem of the Irish land border. Typically, migration and customs controls exist at a land border between a country in a customs union and a country outside that union. The border between Northern Ireland (which is part of the UK) and the Republic of Ireland (which remains an EU member) runs for 499 kilometres, and is the only point at which the UK touches the EU. But since 2011, the UK and Ireland have agreed that there will be no “hard” border between them, and this agreement is regarded as a critical mechanism for avoiding a return to civil unrest in Ireland.

The EU accepted that it would be wrong to impose a hard border on Ireland, but still required customs checks on goods entering its territory. The solution was found in an agreement known as the Northern Ireland Protocol, which formed part of the UK’s withdrawal agreement in 2019. The effect of the Protocol is to treat Northern Ireland as if it were still a de facto part of the EU, so that its border with the Republic remains open, but customs checks are required on goods passing between the rest of the UK and Northern Ireland.

While it was a pragmatic response to a difficult problem, the Northern Ireland Protocol has been politically unpopular with some groups within the UK, and the Johnson government has prepared the Northern Ireland Protocol Bill to give itself the power to override, unilaterally, parts of the Protocol. It has responded to complaints that this is a breach of international law by invoking the concept of “necessity”.

The defence of necessity is an ancient principle of public international law, roughly analogous to the contract law concept of force majeure. Broadly, it means that a state may be excused for an intentionally wrongful act when it was acting to address a situation of grave danger, and had no other option available. The classic situation is a medical emergency: where a plague threatens the health of a country’s population, the government may invoke necessity to disregard patent law to mass-produce and distribute the drugs that cure or prevent the disease. More recently, the concept of necessity has been codified in Article 25 of the International Law Commission’s Articles on the Responsibility of States for Intentionally Wrongful Acts. Article 25 says that necessity may be invoked if the act in question was “the only way for the State to safeguard an essential interest against a grave and imminent peril”.

So how does the Johnson government’s “necessity” argument stack up?

Well, before the defence of necessity can be invoked, there must be an intentionally wrongful act. Customary international law regards a violation of a treaty as an intentionally wrongful act; and the 1969 Vienna Convention on the Law of Treaties provides that treaties may be varied only by agreement of the parties, and should not be repudiated. So the UK’s insistence that it is entitled to modify the Northern Ireland Protocol unilaterally is an intentionally wrongful act.

Next, there must be a “grave and imminent peril”. The Johnson government has invoked this notion, without stating very clearly what the peril is, but hinting at risks of renewed conflict in Ireland. This seems, at best, tenuous. Restoring a hard border on the island might contribute to unrest, but the Northern Ireland Protocol deliberately avoids that. It may be frustrating for Northern Ireland businesses to deal with an increased load of paperwork, but it’s hard to see how that issue would arouse the Irish Republican Army to violence.

But assuming that hurdle were overcome, the Johnson government would face two further difficulties. First, a state may not invoke the defence of necessity when it has “contributed to the situation of necessity”. The UK government contributed to the “situation of necessity” by agreeing to, and signing the Northern Ireland Protocol in the first place. On that ground alone, no necessity defence is available. And the steps taken to address the situation must be the only steps available – but the Northern Ireland Protocol contains its own mechanism – Article 16 – for dealing with difficulties that arise under the agreement. If genuine problems do exist, then Article 16 is the proper channel by which to address them.

Prime Minister Johnson has built his career upon his ability to capitalise on the hostility of his core supporters to the EU. The Northern Ireland Protocol Bill appears to be another political gesture to that constituency, rather than a serious attempt to grapple with complex international trade law issues. Should it become law, it would breach the UK’s international law obligations, and no reputable international lawyer would entertain a defence of necessity.

Necessity is said to be the mother of invention. It also spawns a great many inventive defences. But seldom good ones.