Here is a comment which would have been inconceivable a few years ago: “Looking at the latest decisions of Donald Trump, someone could even think: with friends like that, who needs enemies.” The jarring thing is not the sentiment, but the speaker. It is Donald Tusk, Polish president of the European Council, referring to the US steel tariffs and departure from the Iran nuclear deal. The friendship between the US and Europe has been the most important in the world since at least 1941. Today, it is openly in question.

The next striking point may be the global banking system. The US administration plans to shut Iran out of that system as part of a re-imposed sanctions regime. Perhaps the fastest way to do so would be to end Iranian access to Swift — the Society for Worldwide Interbank Financial Telecommunication — a near-universal secure messaging system which supports cross-border payments. But the Belgium-based utility is under European jurisdiction, and says it only takes direction from Brussels, which wants the international nuclear deal to remain in place.

Iran was shut out of Swift, after years of urging from then US president Barack Obama, between 2012 until the nuclear deal was signed in 2015. But at that time US and continental interests were aligned.