Contestants on Strictly Come Dancing dread the Argentine tango. No matter how good the choreography, it is technically tricky and devilishly difficult to get right.

So the audience was holding its breath as Donald Trump and Xi Jinping got into hold for their own version of the dance in Buenos Aires this weekend. Trade tension between the world’s two biggest economies has increased markedly over the past 12 months and the chances of what Strictly judge Craig Revel Horwood calls a “dance disaster” were high.

In the end, Trump and Xi executed some neat footwork. The trade war is not over but a 90-day truce has been agreed, which means that the 10% tariff Washington has imposed on $200bn of Chinese imports will not be raised to 25% on New Year’s Day. Beijing must then convince Trump that it is meeting Xi’s pledge at the working dinner to substantially increase what it buys from the US.

But before anybody gets too carried away, it is worth injecting a couple of words of caution. For a start, we have been here before. China thought it had a deal with the US sealed in the spring only for Trump to decide to impose tariffs anyway. Protectionism has been playing well with American voters.

Further, the fact that a decision not to go ahead with a new round of tit-for-tat tariffs is seen as some sort of victory speaks volumes about the weakness of international cooperation. Nobody seriously thought the G20 gathering would address any of the global issues it is there to tackle: preventing another financial crisis and co-ordinating a sustainable growth strategy, for example. It turned into the usual excuse for glad-handing and grandstanding for politicians often quite relieved to get away from troubles back at home.

The fact that the meeting was dominated by fears of a return to 1930s-style protectionism is symbolic of the retreat from multilateralism in the 10 years since the first G20 summit in Washington in late 2008. Trump’s trade agenda has not just involved imposing tariffs; he is also threatening to pull the US out of the World Trade Organisation.

Bringing developed and developing countries together made a lot of sense in the fevered atmosphere a decade ago. There was a recognition that decisions could no longer be taken alone by the G7 – the US, Japan, Germany, the UK, France, Italy and Canada. The economic dominance of the big developed countries was being challenged by the fast-growing emerging market economies. There could be no serious discussion about exchange rates that excluded China, no meaningful talks about oil without the inclusion of Saudi Arabia.

What’s more, there was a unity of purpose in Washington and at the G20 London summit that followed a few months later. There was agreement on the need for all countries to limit the damage from the crisis, to use both monetary policy (interest rates and quantitative easing) and fiscal policy (tax and spending) to boost demand, to ensure that the International Monetary Fund and the World Bank had the resources to help countries in trouble, and to avoid putting up trade barriers.

In the early days, there were hopes that the G20 would turn into an effective body for economic global governance. Gordon Brown, who chaired the London summit, envisaged it acting to reform financial markets to avoid a repeat of the 2008 meltdown and agreeing to a global growth pact to underpin jobs and wages.

This proved optimistic. Pressure for reform waned as the global economy stabilised. The big international banks pushed back against calls for serious curbs on their activities. The G20 split between those countries that thought recovery was weak and needed to be supported by a continuation of active fiscal policy and those that thought austerity was necessary to restore budget discipline. There was no common ground between the deficit hawks and the deficit doves, with the result that the G20 was sapped of energy and simply churned out communiques full of drivel.

The lack of concerted action mattered. It contributed to the weakest recovery from recession in living memory, the delay in getting to grips with the eurozone crisis, and the rise of populist sentiment across the developed world.

With the fruits of what little growth there was going mainly to the privileged few, it was not surprising that voters lost faith in multilateralism. A key reason why Trump’s protectionist message resonates with so many American voters is that the trade agenda has been captured by big business: witness the emphasis on protecting intellectual property right and demands that agreements include provisions that allow investors legal redress against nation states for alleged discriminatory practices.

Not far from Buenos Aires, on the mouth of the River Plate lies the small Uruguayan seaside town of Punta del Este. It was here in 1986 that diplomats from around the world arrived to launch a new round of trade talks. The Uruguay round took seven years to complete and resulted in the creation of the World Trade Organisation. It was the last trade round to be successfully concluded; these days deals tend to be cut bilaterally or between groups of like-minded nations.

At Trump’s insistence, the Buenos Aires communique noted that the multilateral trading system was “currently falling short of its objectives and there is room for improvement. We therefore support the necessary reform of the WTO to improve its functioning. We will review progress at our next summit.”

A quarter of a century ago the WTO was seen as the future. Today it could be dancing its last tango. That’s how much things have changed.