There should be no surprise at Tehran’s obdurate and challenging response to President Trump’s reimposition of economic sanctions. The threat to resume its nuclear weapons program, which it has, in point of fact, almost certainly not completely curtailed, is designed to frighten the Europeans who are still clinging to Obama’s lackluster 2015 Joint Comprehensive Plan of Action (JCPOA).

The ayatollahs clearly hope to drive a wedge between Washington and its European allies. This ambition will have been enhanced by the looming possibility of a trade war between the two blocs over Trump’s measures to protect US industry. But it is also typical of a regime that does not “do” moderation. By raising the stakes for any future negotiations, the Iranian leadership thinks it is giving itself big bargaining chips. It is incapable of a more nuanced and sensible response, which it would regard as abandoning a position of strength.

And it is not just the Europeans who could be encouraged to defy the Trump sanctions. China is Tehran’s biggest oil customer closely followed by India and then Korea and Turkey. Beijing is in no mood to make life easier for Trump as it seeks to challenge the US military presence in Asia. South Korea may be more biddable for Washington but Turkey’s President Recep Tayyip Erdogan’s is unlikely to toe the US line. And then there is Russia. During the previous sanctions, the Iranian elite continued to live the good life thanks to extensive Russian smuggling into Iran through a compliant Azerbaijan, which may well have itself profited from the trade.

By many measures, this is a far less propitious time to be trying to threaten the Iranian regime into compliance with international norms. This is, however, not Trump’s fault. Obama had the ayatollahs on the ropes, desperate for an end to sanctions that were undermining their rule, as their already incompetently run economy headed into a nosedive. Yet Obama and his equally incompetent Secretary of State John Kerry threw away the opportunity to have Tehran abandon not just its nuclear program, but also its malign interference in the affairs of its Arab neighbors. Trump is trying to make the best of a disaster engineered by his predecessor, who still enjoys a lofty reputation among liberals worldwide that is out of all proportion to his presidential failures both at home and abroad.

The Iranians will also be hoping that Trump will become completely hobbled by the various scandals which it would seem are now lapping above his ankles. He would thus have no time to combat their machinations.

Iran’s Supreme Leader Ali Khamenei has specifically demanded that European states should defy Washington and continue to protect its oil sales while their banks guard Iranian transactions from US sanctions. Most outrageously, he is insisting that France, Germany and the UK must block any attempt at further negotiations on the JCPOA.

The 2015 Geneva deal was shot through with holes and is clearly not worth the paper on which it is written. This is surely the time for European leaders, no matter how much they may deplore the US president’s behavior, to avoid sitting on the fence. It is not simply a nuclear-armed Iran that they must fear, but the impact of deadly Iranian meddling among Arab states who, they regularly protest, are their friends and allies in the region.