Germany’s Angela Merkel and Donald Trump at the G7 summit. ‘At the political level, the ties that bind us are under strain.’

“I believe that in the North Atlantic treaty lies the best, if not the only hope of peace.” Not my words, but the words of Lord Hastings Ismay, former military assistant to Winston Churchill and the very first secretary general of the North Atlantic Treaty Organisation (Nato).

In the same 1952 broadcast, Ismay predicted “that there will be persistent efforts to drive a wedge between us” and “that we shall have our little quarrels”. Right now, those words seem remarkably prescient.

Since the alliance was created almost 70 years ago, the people of Europe and North America have enjoyed an unprecedented period of peace and prosperity. But, at the political level, the ties that bind us are under strain. There are real differences between the US and other allies over issues such as trade, climate change and the Iran nuclear agreement.

These disagreements are real and they won’t disappear overnight. Nowhere is it written in stone that the transatlantic bond will always thrive. That doesn’t, however, mean that its breakdown is inevitable. We can maintain it, and all the mutual benefits we derive from it.

It will take political will, imagination and hard work. But I believe we can succeed, for three simple reasons.

Firstly, differences of opinion are nothing new. We had them during the Suez crisis in 1956. We had them when France withdrew from Nato’s command structure in 1966, and the alliance had to move its headquarters from Paris to Brussels. And we had them during the Iraq war in 2003.

We are 29 democracies with different histories, geographies and cultures, so of course we sometimes disagree. But the historical record shows that, despite our differences, we have always been able to unite around our common goal: standing together and protecting each other.

The second reason we can preserve the transatlantic bond is what…