I added a question to your chatGPT link. Which treaties the UK cannot get out.
It is even more important to know them than those we can renounce.
In principle, the UK can withdraw from almost any treaty, since international law recognises a right of denunciation or withdrawal if the treaty itself provides for it (e.g. Article 50 TEU for Brexit), or under the Vienna Convention on the Law of Treaties if there’s fundamental change, material breach, or consent of the parties.
But there are categories of treaties the UK “cannot get out of” in any realistic sense:
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1. Peremptory Norms (Jus Cogens)
These are rules of international law that no state can derogate from by treaty or withdrawal, e.g.:
Prohibition of genocide
Prohibition of slavery
Prohibition of torture
Prohibition of aggressive war
Even if the UK signed a treaty allowing slavery, it would be void under international law.
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2. UN Charter Obligations
As a founding member of the United Nations, the UK is bound by the UN Charter.
Article 103 of the Charter gives its obligations priority over any other treaty.
While in theory the UK could leave the UN (Article 6 allows expulsion, but there’s no formal withdrawal clause), in practice leaving would mean cutting itself off from the Security Council and the entire UN system. It’s politically close to impossible.
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3. Customary International Law
Some rules bind all states regardless of treaties, such as:
Immunity of diplomats
Law of the sea basics (e.g. innocent passage)
Withdrawal from a treaty like the Vienna Convention on Diplomatic Relations wouldn’t free the UK from the customary rule.
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4. Treaties with No Exit Clause (or very hard exit)
Some treaties lack explicit withdrawal provisions, making exit diplomatically explosive. Examples include:
European Convention on Human Rights (ECHR): the UK could denounce it (Article 58 ECHR), but it would mean leaving the Council of Europe, undermining Good Friday Agreement commitments in Northern Ireland, and facing huge political consequences.
Nuclear Non-Proliferation Treaty (NPT): has a withdrawal clause (Article X), but given the UK’s status as a nuclear-weapon state under the treaty, leaving would trigger global crisis and heavy sanctions.
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Summary:
Legally, the UK can denounce almost any treaty with the right procedure.
But it cannot escape jus cogens norms, UN Charter primacy, and customary law.
Some treaties are technically escapable (ECHR, NPT, WTO), but doing so would come at such enormous political and economic cost that they are practically “non-leavable.”
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Would you like me to make you a table of key UK treaty commitments (ECHR, NPT, WTO, NATO, UN, etc.) showing whether exit is legally possible, politically possible, or impossible? That could give you a quick-reference “at-a-glance” map.