Call it coincidence if you like but years that end in a “9” have a habit of being eventful. More particularly, they tend to be years of upheaval. There’s 1789, of course, the year of the French Revolution. The Peterloo massacre, which eventually led to the launch of the Guardian, took place in 1819 and a century later there were fears that Bolshevism would spread from Russia westwards.

The year 1939 requires no further explanation while 1979 encompassed the Iranian Revolution and the arrival of Margaret Thatcher in Downing Street. A decade after that, the tearing down of the Berlin Wall heralded the collapse of communism. In 2009, central banks had to pull out all the stops to prevent the deepest recession since the second world war turning into a second Great Depression. The slump against which all others are measured began with the Wall Street crash of October 1929.

But it is not just history that suggests there could be trouble – and plenty of it – ahead in 2019. The Cassandras predicting a return to the crisis conditions of a decade ago are feeling smug. There is plenty for those of a pessimistic disposition to fret about.

As in 2008-09, all eyes are on the US. The world’s biggest economy performed strongly in 2018, with robust growth and unemployment at levels not seen for the best part of half a century. But it won’t last. Activity has been boosted over the past year by Donald Trump’s tax cuts, but the impact of looser fiscal policy is now starting to ebb. What’s more, the Federal Reserve, America’s central bank, has been gradually ratcheting up interest rates – in part because it fears the tax cuts will lead to an overheating economy.

The Fed has also begun the process of reversing the bond-buying programme it used to create money and stimulate growth from late 2008 onwards. Quantitative easing has been replaced by quantitative tightening, and whereas QE helped fuel a boom in asset prices, particularly shares and property, QT is doing the opposite. Last week’s 1,000-point rise in the Dow Jones Industrial Average looked impressive but followed a two-month period in which all the world’s leading stock markets had been in full retreat. Further volatility seems inevitable.

It hasn’t helped that 2018 marked the closest the world has come to a full-scale trade war since the 1930s. Having campaigned as a protectionist, Trump made good on his promises. There were skirmishes with Canada, Mexico and Germany but most of the White House’s firepower was directed at China.

The first couple of months of 2019 will be crucial if the tension is to be defused. Trump and China’s president Xi Jinping struck a deal at the Buenos Aires G20 summit in early December, and in return for agreeing to import more American goods the US agreed to hold a tariff increase from 10% to 25% on $200bn worth of imports. But only for 90 days. If Trump thinks China has not done enough, the trade war will be back on.

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Xi would like to avoid that outcome if at all possible. China’s economy – while still posting growth rates far higher than in the west – is expanding much less rapidly than it once was. The country’s communist leaders are trying to move from an economic model dependent on cheap credit and state investment in white elephant infrastructure projects to one with slower but higher quality growth. It is proving a difficult trick to finesse.

Either or both of the world’s two biggest economies could trigger a global crisis in 2019. The other member of the “big three” is the European Union and there is plenty of potential trouble there, too.

Europe faces challenges both economic and political. A period of above-trend economic growth engineered by the European Central Bank has run its course. Activity is slowing and there is an acute awareness that the weaknesses in the architecture of monetary union exposed by the last crisis have not been rectified.

To do so would involve Germany agreeing to plans for a European finance minister overseeing a pan-European fiscal policy that would raise taxes from the richer parts of the eurozone to increase spending in struggling countries. But taxpayers in Germany have no desire to write cheques for less prosperous countries and Emmanuel Macron, the politician keenest on pushing ahead with the integrationist project, is a busted flush.

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The gilets jaunes protests in France, the arrival of an avowedly populist government in Italy, and Brexit, are all political manifestations of deep economic unhappiness caused by years of weak growth, stagnant real wages and rising inequality.

A chaotic exit from the EU by the UK in March is clearly a short-term risk – for Britain, for the eurozone and for the wider global economy. But there are other potential flash points – Belgium Poland, Hungary, France and, of course, Italy, where relations with Brussels remain problematic despite recent progress in the row over Rome’s plan for an expansionary budget.

A stock market crash; a trade war; higher US interest rates triggering debt crises in overextended developing countries; an oil shock that stems from political upheaval in Iran or Saudi Arabia; these are all easy to identify as things to watch out for in 2019.

But what of the events that are harder to spot? Here are three to be going on with: a deterioration in the relationship between Russia and the west; a full-scale cyber-attack that shuts down the world’s financial markets and a year of extreme weather events caused by climate change. We are in for a hot 2019, in more ways than one.