There are four major power blocs in the world — the United States, Russia, China and the EU. Of these, only the EU does not provide for its own defence and security. Remarkably, nearly 75 years after the end of the second world war, Europe is still heavily dependent upon the United States for its defence. But it is hardly surprising that, in the Trump era, pressure has grown for an autonomous European defence policy.

The question of how Europe is to be defended in the post-Brexit era has yet to be examined. The EU has, for some years, been seeking ‘strategic autonomy’, though it is never wholly clear precisely what that means. But in February 2015, Ursula von der Leyen, the German defence minister, called for a European army, a call echoed by Jean-Claude Juncker a month later, who declared that such an army would convey to Russia ‘that we are serious about defending the values of the EU’. More recently, Emmanuel Macron has given his imprimatur to the idea. In his 2017 Sorbonne speech, he spoke of Europe developing ‘autonomous operating capabilities’, a concept as nebulous as ‘strategic autonomy’.

Britain has always, with good reason, been sceptical of an integrated European defence policy, believing that it would undermine Nato and divert energies better applied to strengthening it. Moreover, such a policy could, in theory, require that a country would be committed to war against its parliament’s own wishes; while if military action required unanimity, every member state would have a veto, and that would guarantee that nothing would be done.

In the major foreign policy crises of the past two decades — Kosovo and the Iraq war — Europe has been divided, while today EU members such as Austria, Cyprus, Hungary and Italy find themselves more sympathetic to Russia and China than do the vast majority of member states. When Yugoslavia disintegrated in 1991, Jacques Poos, Luxembourg’s foreign minister, declared that ‘the hour of Europe has dawned’. But the EU seemed impotent and unable to prevent the ethnic cleansing of Muslims in Bosnia, the worst crime that Europe has seen since the Holocaust. It has proved equally impotent during the Syrian civil war. High–sounding aspirations by Europe collapse when tested by reality.

The truth is that, for collective defence to be effective, the units to be defended must see their separate interests as subordinated to a common good. That might happen at some future date in Europe, although one is entitled to be sceptical. It is certainly not the case today. And it is not to be created by labelling something a European defence policy.

President Trump has called for Europe to take greater steps to defend itself. Hillary Clinton, had she been elected, would have said the same, though no doubt in somewhat softer tones. Regardless of who is in the White House, most Americans believe that Europe should bear more of the costs of the continent’s defence. And America is in any case becoming immersed in the problems of the Asia/Pacific area, a trend that preceded the election of Trump and will almost certainly continue after his presidency has ended.

There is, therefore, a strong case for Nato becoming a two-pillar alliance, with a strengthened European pillar. That pillar, however, must be intergovernmental, and it must include Britain. For Britain is one of just eight members out of Nato’s 29 to meet the target of 2 per cent of GDP devoted to defence spending, and is the second-largest spender on defence in Nato, behind only the United States. Of the other large states in Europe, Germany — for obvious historical reasons — cannot lead on defence, where, by contrast with the economy, she must be a follower, not a leader. Therefore European defence must depend primarily upon Britain and France, the only nuclear powers in Europe, and two powers in the vanguard of resistance to the illiberal trends which are disfiguring the continent.

However, Britain is now leaving the EU, so if European defence is to be intergovernmental, and if it depends primarily upon Britain and France, it cannot be developed within an EU framework. Charles de Gaulle believed that if Europe wanted to be a power in the world, that could only be achieved outside the EU through a directorate of the major powers. That was the basis of his Fouchet Plan in 1962, and his proposal in 1969 to the British ambassador, Sir Christopher Soames, that a four-power directorate outside the European Community be established, comprising Britain, France, Germany and Italy, to be responsible for foreign policy and defence.

Theresa May has said many times that, although Britain is leaving the EU, we are not leaving Europe. The safety of Britain is, as it has always been, closely bound up with the safety of Europe, and in particular with the safety of France. Indeed, in the first half of the 20th century, a firmer alliance between the two countries might well have prevented both world wars. Today, the strength and stability of France and the success of President Macron as the leader of liberal Europe is as much a British interest as a French one, just as the success of post-Brexit Britain is a key French interest. Sadly, neither the British nor the French seem to recognise this. But if liberal Europe is to be preserved and able to defend itself, it is high time for the current discord to be replaced by a renewal of the entente cordiale.