The G20 riots were a reminder to us that Germany does the whole police state thing very well: military vehicles, water cannon, pepper spray and a baton in the face of anybody standing in their way. To a British political class nervy about both mobs and Marxism since the Grenfell disaster, the sight of Hamburg in flames cannot have been reassuring. Because what the Hamburg troubles showed is that the anger simmering across western societies has become systemic.

Events so dramatic that even unpoliticised people notice them are punctuating the present: Brexit, Donald Trump’s victory, the riotous ejection of Milo Yiannopoulos from Berkeley; terrorist attacks in France, Germany and the UK; the Front National’s surge and Emmanuel Macron’s tsunami; Theresa May’s debacle ... history is thumping stability.

If the global elite had stuck to the strategy it outlined at the last G20, in Hangzhou, the weekend’s violence could be shrugged off. Yet in the space of a year, the response of the politicians and bankers who call the shots has changed in two ways.

First, among the central banks, a “tightening” cycle has begun, whereby they begin to withdraw the low interest rates and money-printing operations that have kept the world economy afloat since 2009. That means the credit and stock market frenzy of the past 18 months may soon end.

Last year, Bank of England governor Mark Carney, among others, assured the G20 finance summit that central banks could – if permitted – do a lot more to buy time for the politicians to find a new economic model for the world. But no new model has been forthcoming. Instead, with the election of Donald Trump, the consensus around globalisation itself has begun to fall apart.

That leads to the second big change at Hamburg: on trade. One of the main reasons for convening the G20, which first met in 2008, was a joint pledge to avoid protectionist responses to the financial crisis. As trade expert Prof Simon Evenett points out, this pledge “has been broken every 13 hours since it was agreed”, as governments racked up 5,886 new trade restrictions.

The usual bland statement against “protectionism in all its forms” was replaced with a pledge to “fight protectionism including all unfair trade practices and recognise the role of legitimate trade defence instruments in this regard”. That’s the difference between saying “war is bad” and “if someone declares war on you, blitzing their capital city is legitimate self defence”.

And one of the worst things about the incipient trade war is that the rhetoric is always tougher than the actions. You “dumped” steel on me, you cheat, so I will embargo your stinking bourbon whiskey, is the general tone of things. So, as they embrace “legitimate trade defence”, the nations go on adding to the stores of anger in the world.

Indeed, for Trump and Vladimir Putin, there is a clear calculation: the more angry their own people are with foreign countries, products and human beings, the less likely they are to stage their own version of the Hamburg protest. Hungary’s Viktor Orbán has, this week, made his own contribution to the rising anger in the world by plastering Budapest with posters depicting George Soros as an enemy of the Hungarian people.

We are at a stage in global politics where the rising anger can be directed in only two directions: upwards, at the elites themselves, or sideways – towards minorities, rival nations and the institutions we rely on to maintain the rule of law.

In the UK we are awash with pleas for less anger: from Labour MPs scared of their own members, a Tory leadership scared of its own backbenchers, and columnists lamenting the discourteous tone that has crept into the debate over why so many poor people were incinerated at Grenfell.

Before I add my plea, it is important we recognise where the anger comes from. For people without economic power, everyday life can seem like one long act of coercion against them. You must wait in line for benefits, hospital treatment, the GP surgery, housing advice. You must never show frustration, or formal sanctions will kick in. For workers in the most precarious jobs there’s a hidden system of fines and demerits, compulsory overtime, and managers allowed to behave like small-scale Putins, Trumps and Orbáns. This is one of the reasons life in the UK feels so orderly, but it is also what makes people’s actions once they snap less predictable.

The strongest antidote to anger is a democratic political system that allows dissent to be expressed, which reacts swiftly to genuine grievances and has strong local networks through which people feel empowered. The G20, which includes two outright dictatorships and at least four more ruled by corrupt autocrats, countered the fury of Hamburg’s streets with a communique mentioning everything from water rights to antimicrobial resistance. Everything, that is, except democracy.

So let’s lament the burned-up Audis of Hamburg, and work to ensure Britain’s summer of discontent with Theresa May is peaceful. Let’s also remember that five of the biggest trouble-stirrers on the planet were staring out from the G20 photo: Narendra Modi, Putin, Trump, Recep Tayyip Erdoğan and Xi Jinping. King Salman of Saudi Arabia was otherwise engaged trying to crush a neighbouring country.