One hundred years ago, Woodrow Wilson boarded the SS George Washington and set out for Europe. The American president had a plan he believed would prevent a repeat of the war that since 1914 had savagely torn the planet apart.

After nine days at sea, he arrived at Brest in France, then travelled overland to Versailles to meet his fellow global leaders. "I can predict with absolute certainty that within another generation there will be another world war if the nations of the world do not concert the method by which to prevent it," he said. Wilson unveiled his 14 Points, which would create an international organisation where disputes could be talked through and mediated, and the peace be kept. This was the beginning of the League of Nations. Two years later, Wilson received the Nobel Peace Prize for his efforts.

Although 40 countries signed up, in the end the League failed – not least, ironically, because Congress prevented the US from joining. As Wilson predicted, there was another world war. From this second terrible conflagration emerged the United Nations, a successor to the league that, for all its flaws, has proved considerably more effective and durable.

In today’s globalised world, in which a tweak on a string in one country can topple great institutions in another, and in which American hegemony is under challenge for the first time since the end of the Cold War, the UN has never mattered more. As the post-1945 settlement frays, the Security Council bears a heavy burden. It is there that the five permanent members – the US, UK, Russia, China and France – make decisions about war and peace.

We enter 2018 hoping to draw breath after a turbulent and distressing 2017, but the sad reality is that the near future is likely to hold more instability and greater risk. We are only at the beginning of things.

Consider those all-important permanent members. Let’s start with China, which becomes more cockily muscular by the month. In his speech to the Communist Party’s 19th national congress in October, President Xi, perhaps the country’s most powerful leader since Deng Xiaoping, made an overt strategic shift by stating China would become a "leading global power" with a "first-class" military by 2050.

"A military is built to fight," Mr Xi said. "Our military must regard combat capability as the criterion to meet in all its work, and focus on how to win when it is called on."

The retrenchment of the US under Donald Trump is emboldening the Chinese to seek a front-rank role in world leadership, politically, economically and militarily. For a growing number of countries, China’s authoritarian state-capitalism is seen not just as a different brand to the West’s liberal capitalism, but as a possible replacement.

It’s estimated China spends $10-12 billion a year on foreign influence. In recent weeks, the intelligence services of Germany and New Zealand warned publicly about activity in their countries, while Marco Rubio, chair of the US congressional executive commission on China, stated that "attempts by the Chinese government to guide, buy, or coerce political influence and control discussion of 'sensitive' topics are pervasive, and pose serious challenges in the United States and our like-minded allies." Christopher Johnson, a former head of the China desk at the CIA, puts it more starkly: "As we start to realise that China intends to socialise us rather than become more like us, the debate in the West has taken on a harder edge and people are asking whether 40 years of engagement might have been a sham." You don’t have to look to hard to see that conditions for a potential Great Power conflict are being sewn.

That’s before we come to Russia, where Vladimir Putin has just announced he intends to seek (and will therefore win) another six-year term in office. This will take him into his 70s, and will likely be his last, making his 24-year reign – including a short spell as PM – the longest since Stalin’s. It would be foolish to think anything other than that Mr Putin will want to energetically leave a legacy as a great historical leader who made Russia a rival to the US once again. His methods are well known: aggression, subterfuge, interference in other countries’ internal elections and affairs, and extra-legal assassinations. "This is a new generation of warfare that is continuous and ongoing," Elina Lange-Ionatamishvili, of the NATO Strategic Communications Centre of Excellence, has said. "The goal is to confuse, distract, and blur the lines between war and peace."

It’s not as if Europe lacks its own problems. In a new report, researchers at the Tony Blair Institute track the worrying rise of populism across the continent. Extremist parties have already taken power in Bosnia, Bulgaria, the Czech Republic, Hungary, Poland, Serbia, and Slovakia. They "tend to emphasise a nationalism based on soil, blood, or culture; take a hard line against immigration; and… dismantle key democratic institutions like the free media and an independent judiciary." In Germany, the right-wing AfD and the hard-left Die Linke now make up a quarter of the Bundestag. "Populists might prove to be a mostly innocuous interlude," the report says, "or it could be a harbinger of 'democratic deconsolidation,' raising the prospect that the future of democracy is more embattled in Europe than most social scientists have long believed."

These uncertain conditions are why centrists like me worry about the tolerance of political extremes, here and elsewhere. The US has an unstable fool in the White House and is a country bitterly divided against itself. The UK is consumed by Brexit, a separation that is building walls, souring alliances and bolstering the idea that the West’s day is done.

In short, the good guys aren’t paying attention. As the great strategist Sir Lawrence Freedman writes in his new book, The Future of War, there is a "tendency… to assume that the recent past can be extrapolated into the future, that trend lines will continue, as with claims that war as an institution is in inevitable decline. War… has a future." Can we really find the unity to prevent one?