On Wednesday, British Prime Minister Theresa May sent a letter to the president of the European Council in Brussels stating that under Article 50 of the Lisbon Treaty, Britain was leaving the European Union. This signals the start of negotiations for a British divorce from the union and for the development of a new relationship between Britain and the EU. These negotiations have to be completed within two years unless both sides agree to an extension.

The negotiations will be difficult and complex. Both the British and EU negotiators will be under significant pressures from all the various interested parties and from popular opinion as expressed in parliaments in the United Kingdom and in EU countries as well as in the media. There will be a lot of hot air and inevitably some emotional outbursts. Reasoned discussion and a realistic understanding of the facts are needed. The negotiators on both sides need to exercise restraint and be willing to search for mutually acceptable compromises.

The first requirement is to agree on a process for negotiation. The EU wishes to settle the financial and legal terms of the divorce before negotiations about trade and future relations. The British want these negotiations to be conducted in parallel.