Leader comment: Security warning sets ominous tone for Brexit

Given the error-strewn path taken by the UK government since last summer's EU referendum, it should come as no surprise that on the day Article 50 was triggered, there were further gaffes.

Britain's ambassador to the EU Tim Barrow delivers Theresa May's formal notice of the UK's intention to leave the bloc to European Council President Donald Tusk. Picture: Getty Images

Whatever expectations there were that Prime Minister Theresa May would strike a conciliatory tone on one of the most significant junctures in British political history, the records will show she took the opposite stance.

Instead of reaching out to Europe, she effectively issued a thinly veiled threat by raising the spectre of weakened security relations post Brexit.

Any failure to reach agreement between the UK and the EU, she said, “would mean our co-operation in the fight against crime and terrorism would be weakened”.

In her letter to Donald Tusk, president of the European Council, which contained no fewer than 11 references to security issues, she added: “In this kind of scenario, both the United Kingdom and the European Union would of course cope with the change, but it is not the outcome that either side should seek.”

While there can be little doubt that Britain’s security and military apparatus – coupled with its close ties with US agencies – is the envy of Europe, such remarks felt ill judged. In countries such as Belgium and France, which like the UK, have felt the brunt of terror attacks in recent years, Mrs May risks being seen as crass and insensitive.

If, as seems to be the case, she sincerely believes trading security for prosperity is an acceptable opening salvo in what will be long and torturious negotiations, her reading of situation is clumsy and damaging.

Terrorism, as the west well knows, does not respect borders or constitutions, and whatever form the UK’s future relationship with the EU takes, working closely with our European neighbours will be fundamental to tackling a global problem.

As Tim Farron, leader of the Liberal Democrats, pointed out: “Security is too important to be used as a bargaining chip and this will backfire in any negotiations, which rather than building up alliances will leave Britain even more isolated.”

After widespread criticism of Ms May’s letter, Downing Street attempted to backtrack, insisting it referred only to security arrangements agreed via the EU, such as the European Arrest Warrant and Europol.

But by then, the damage had been done. Less than 24 hours after Article 50 was triggered, the UK finds itself on the back foot and a needlessly aggressive tone has been set.

Given the hostile contents of Ms May’s letter, the frosty reception on the continent was entirelty predictable. A sombre-looking Mr Tusk delivered his own farewell message to the UK. “We already miss you,” he said. “Thank you and goodbye.” If nothing else, it was a remark which ought to impress upon British negotiators that Mr Tusk’s considerable armoury includes sarcasm.

The next two years will shape Britain’s future standing in the world. Yesterday may be symbolic in more ways than one.