In 1974, the great French film director Jacques Rivette, by then almost the last man standing from the postwar generation of Nouvelle Vague cineastes, released what remains the most repetitive film I have ever seen. It was called “Celine et Julie vont en Bateau” (Celine and Julie Go Boating). It lasted three-and-a-half hours and was essentially a story about a series of events retold over and over again, seen from different angles, with different plot emphases and an admixture of magic, but never reaching a conclusion. At the time, I thought it was enormously profound, like the novels of Alain Robbe-Grillet. Now I’d rather eat broken glass.

And that, in short, is what the Iran negotiations in Vienna have become: A high-end soap opera whose protagonists constantly announce that they are almost there, only for that “almost there” to become another chapter with no ending. And the definition of closure changes subtly too. The EU representative will say that only a few loose ends need clearing up. The Iranians will say that their opponents need to be “realistic” (which clearly means something different in Farsi to its sense in English). The Russians will say that we need to make one final push and a new world of peace and prosperity for all is just around the corner, suggesting sotto voce that the US in particular is the obstacle. The US, meanwhile, will suggest a deal is perfectly doable, that it needs to be done tomorrow and that maybe it will never be done. It is all very confusing.

Interestingly, we see similar confusion over the current war in Ukraine. The Russians say they are winning. They then say they are withdrawing combat forces into Belarus for recuperation and intend to focus on the Donbas region in the east — where they had success with their signature version of hybrid warfare and disorienting disinformation campaigns after 2014. But these techniques do not seem to be working so well this time around. When Moscow publishes photographs or video footage designed to show Ukrainian forces mistreating Roma, for example, it turns out very quickly to be fake. When Ramzan Kadyrov has himself photographed apparently in the theater of war, he turns out to be next to a Rosneft service station — which do not exist in Ukraine — or actually in Grozny. The Ukrainians, meanwhile, are smarter and faster, with their president in particular being a spectacularly effective communicator. Vladimir Putin just looks as if he has put on weight.

It is still very hard to work out what is actually going on, although it seems pretty clear that the Russians did not expect to meet such fierce and sustained resistance, have lost serious numbers of men and kit, and have shown themselves to be incompetent at the core enabling tasks of an army: Training, planning, intelligence and logistics.

And yet these two separate but connected issues — the Joint Comprehensive Plan of Action and Ukraine — are central to the way the world will look in the future. They both reflect the way in which disruptive and revanchist states have emerged to challenge what they perceive as the Western-dominated post-Second World War international order, based on a dispute resolution mechanism centered on the UN Security Council and the open trade economic norms encapsulated in the Washington Consensus of the International Monetary Fund and the World Bank.

Two separate but connected issues — the Iran nuclear deal and Ukraine — are central to the way the world will look in the future.

Sir John Jenkins

You can certainly criticize these institutions. They undoubtedly serve US interests. And they were made at a moment when global politics was dominated by Western powers. But that is just life. No international order is viable if it is not backed by hard power. After the Second World War, the US was the unquestioned hyperpower, whose security capabilities guaranteed the stability of Western Europe, Japan, Korea, Canada, Australasia and large parts of the Middle East. This helped the US sustain its political and economic dominance.

But it was also massively beneficial for lots of other people too. If you think that a more multipolar world will produce the same extraordinary surges in global well-being that the nearly 60 years from 1945 to 2003 did, then you are almost certainly mistaken. There are other forces at work, of course. Climate change, huge pressure on energy and other natural resources, environmental degradation, migration, the internet and social media, new and virulent cultural and political conflicts, the rapid rise (or perhaps I should say revival) of China, and so forth.

Our collective interest in withstanding attempts to seize the territory of another sovereign state by armed aggression or to subvert and destroy the capacities of other states in the interest of predatory, rapacious and entirely unrepresentative elites is now being tested in these two theaters — those of conflict in Ukraine and of negotiations in Vienna. And these are also tests of our collective ability to resolve all other global challenges. Simply thinking that Ukraine or Iran is a localized problem entirely misses the point. They are symptoms of a global malaise.

And part of that malaise is the recent failure or inability of the US to exercise effective global leadership. There are material reasons for this. America’s global share of world trade is now a fraction of what it was in 1950 — and significantly less than it was even 10 years ago. The conflicts in Afghanistan and Iraq imposed serious strains on the political fabric of the country and on its armed forces. They also cost several trillion dollars. And the end of the Cold War reduced the need for Western solidarity and produced the illusion that we had entered a new and conflict-free age of enlightenment. We had not, of course, not even in Europe, some of whose politicians were rather too eager to cast themselves as philosopher kings or queens. The Balkan wars should have been a warning. Instead they were seen as an aberration.

Some political leaders retained the ability to see clearly. Laurent Fabius, the then-French foreign minister, wrote an illuminating piece for The Washington Quarterly in 2016 about the first JCPOA negotiations and their outcome. He explained the way in which the Iranians gamed the US and the salutary pushback from Paris in particular. We need this sort of hard-headed pragmatism again. It is certainly arguable that we are indeed seeing this from the Biden administration over Ukraine, where US (and British) intelligence has been adroitly deployed to deny Russia control over the information environment, while Washington and London have been the major suppliers of serious operational military assistance to Kyiv. It would be nice to think this is what we are going to see over Iran too.

However, the signs there are very mixed. The US has imposed some welcome new sanctions on individuals and institutions associated with recent Islamic Revolutionary Guard Corps attacks in Iraq. And, so far, Washington seems to be holding firm on the question of the designation of the IRGC as a foreign terrorist organization. But the US delegation in Vienna seems divided. The highly experienced Dan Shapiro, who served as US ambassador to Israel and remains close to Israeli political and security leaders, last week became the second senior figure to leave this year. Whether these events represent serious differences of view over the approach to Iran and the IRGC in particular — with Rob Malley, the leader of the delegation, being more inclined to give Tehran what it wants — remains unclear. But it is worrying. And these worries are clearly part of the background to the current tensions between the leaders of some Arab Gulf states and Washington.

The Biden administration needs to decide quickly who it believes its real partners are in a world that is becoming more polarized and conflict-ridden by the minute. That cannot be a question of absolutes. It is a matter of consistency. It is a matter of communication. And, above all, it is a matter of priorities. But what are they?

• Sir John Jenkins is a senior fellow at Policy Exchange. Until December 2017, he was corresponding director (Middle East) at the International Institute for Strategic Studies, based in Manama, Bahrain, and was a senior fellow at Yale University’s Jackson Institute for Global Affairs. He was the British ambassador to Saudi Arabia until January 2015.