Perhaps we could start with the Norman conquest. On the death of Edward the Confessor there were three claimants for the crown of England, Harold Hardrada, a Viking, William of Normandy and Harold Godwinson of Wessex, the largest kingdom in England. The Witon, the English council of noblemen, decided that Harold Godwinson should get the gig and he was crowned that day. Harold Hardrada, claiming that Edward had promised him the throne, invaded from the North. He was killed in the battle with Godwinson.

Which left the forthcoming invasion from Normandy at the other end of the country to be dealt with. William claimed that Edward had promised him the throne in 1051. William also said that Harold Godwinson had sworn an oath that he would help William take the throne after Edward’s death. This was in return for his having liberated Godwinson when he had been taken prisoner in Normandy in 1064. One scene from that impartial historical record, the Bayeux tapestry, an early version of ‘Horrible Histories’, shows Harold taking the oath on piles of holy books and relics.

So then, ‘international law’ was what the aristocrats decided between themselves should happen, sometimes backed up by religion. And if they couldn’t agree? They battled it out.

And so, apart from some diplomatic attempts at definition of how states should conduct themselves, there was no agreed, written, general-purpose international law. And that continued until an attempt at codification with the creation of the United Nations.

Countries have since tried to justify their bellicose actions under international law, but it has rarely actually changed anything for the better. Its main success has been in the prosecution of war criminals both in the aftermath of WWII and subsequently when dictators have been deposed – and, unusually, lived to tell the tale.

Self-defence as, permitted by international law, is the supposed justification for the present carnage in the Middle East. As individuals, we may use only the amount of violence reasonably required to defend ourselves (or someone-else) from harm. If someone threatens to hit me I am not entitled in the UK to use a gun in self-defence. It would be disproportionate.

But what if I have a neighbour who is openly making a bomb which he says he will use to blow up my house, with me in it? Fortunately, I can go to the police once I know about the risk and ask them to arrest him.

But what if there isn’t a police force to call on? Do I have to wait until the bomb’s fuse is lit before I react; until there is an imminent risk that he will carry out his threat? Could I not instead, perhaps with friends, break into his house and remove his bomb-making materials?

This, in a rather untidy way, is meant to be an analogy of the international situation: we do not have an international police force able to keep the peace by intervening early where there is a threat. The authority in these things, is the UN Security Council. Although Its decisions are theoretically binding, they are subject to veto by the permanent members. Which leaves us asking what standing international law actually has if it is routinely overridden by political interests and usually unenforceable.

We are told that international law comes from treaties and ‘customary law’ – including case law. The basic right to self-defence though is actually spelt out in a UN charter. It says: ‘Nothing...shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations’. On the face of it then pre-emptive self-defence is not permitted. Article 51 requires an armed attack actually to have occurred before a state can act in self-defence.

However, as the right expressed in article 51 is “inherent” then it does not mean that the right as expressed is a comprehensive definition. It allows customary international law to be considered as well as what is written in the treaties.

The accepted customary law extension to the wording says that anticipatory self-defence is justified if there is “a necessity for it which is instant, overwhelming, leaving no choice of means, and no moment for deliberation,” and it must be proportionate.

That though was agreed in correspondence between an American diplomat and a British diplomat in the 1840s in connection with cutting the moorings of an old ship, the Carolina, so sending it over Niagara Falls. It had been used for sneaking saboteurs into the then dominion of Canada from America.

The definition though does not allow for the weapons we have today, their range, speed and destructive power.

And a wider interpretation was used by Israel in June 1967 when it destroyed much of the Egyptian air force on the ground prior to an anticipated Egyptian attack on Israel.

It seems only too obvious that sometimes carefully considered pre-emptive action is required. If not, I wonder what the point of international law is.

Over the years Iran has been building up armaments and funding proxy groups with the openly declared aim of wiping Israel of the map. So then is Israel, with the help of friends, entitled to take pre-emptive action? Must it wait until there is an imminent risk of attack? None of us want to rely for guidance on Trump’s conscience, but the difficulties and scope for different interpretations inherent in international law are on full display at the moment.

There is though a clear difference between self-defence and revenge and what started off as a matter of self-defence has now turned into reprisals in that other, related, theatre of war, Gaza.

And, with Israel calling the shots, it looks very much as though that is what we shall see with Iran: it is after all, the source of weapons for the proxy groups in Gaza and in Lebanon. Why would Israel change its policy? Particularly as they seem to have encouragement from Trump.

And this would not be the first time that reprisals will have occurred. Back in 1986 under the Reagan administration, bombs were dropped without warning on Libyan military bases in revenge for a terrorist attack on a Berlin discotheque that resulted in the deaths of American servicemen. The U.S. attributed the attack to Libyan-supported terrorists. On that occasion Margaret Thatcher approved flights from the UK while France and Spain said no. The airstrikes resulted in the deaths of 63 people, including members of Qaddafi's family.

I’m not though convinced that international law even exists. Why? Firstly because its unenforceable. Domestic laws are capable of enforcement. International law is therefore in a category all of its own – perhaps that of advice and guidance?

Secondly, those ‘laws’ are subject to a major democratic deficit, at least here in the UK. They are agreed between governments. It was only in 2010 that treaties were even required to be laid before Parliament. The justification for the former absence of parliamentary scrutiny was that they could not have an effect on our domestic law.

But even now, treaties are rarely debated. And so they will have received at best a cursory examination by our Parliamentarians. Under our new system, twenty one days notice of the intention by the government to ratify a treaty is given to Parliament - along with an explanatory memorandum. If no objection is made, it is approved. If the Commons passes a motion objecting to the treaty (something so far not done) then the 21 day period starts again.

So then, for laws intended to have, well, ‘international’ consequences, it is very difficult to give them democratic justification: problematic, to say the least.

I do not therefore see how there can be recognition of international law as a stand-alone concept. And in the absence of effective ‘policing’, the strong are not going to abide by international ‘law’. They will cite it only when it suits them.

In the minds of international law lawyers, international law may well exist and maybe the foundational treaties will not actually be abrogated, but the inability to enforce the ‘law’ makes it effectively toothless. And I don’t think that insisting on the reality of a toothless form of law does us any favours.

9th March 2026

Paul Buckingham