

Last autumn Boris Johnson, the new prime minister, ordered his chief Brexit civil servant, David Frost, a former UK ambassador to Denmark and director of the Scotch Whisky Federation, to reverse existing UK policy and accept proposals from the EU formulated by Michel Barnier, to write into a new Treaty, the Withdrawal Agreement, guarantees that there would be no border checks in the north of Ireland between the six counties in the UK and the rest of the Republic of Ireland.

Britain has been busy for centuries signing Treaties governing its relations with other states or multi-state entities as well as international organisations like the UN, the WTO, or the EU. Until Brexit the UK’s relationship in most areas with other European sovereign nation states has been fixed by various treaties such as the Treaties of Maastricht, Nice, Lisbon, or the Single European Act treaty negotiated by Margaret Thatcher introducing the Single Market. Pacta sunt servanda – treaties must be observed – is an ancient rule of relations between states. How the Brexit negotiations can end without war being declared, asks Denis MacShane? What’s needed is a compromise, which used to be a British speciality, he argues.
