The first round of the French presidential election has confirmed the new trend in international politics. In country after country, the most important political division is no longer between left and right - but between nationalist and internationalist.

The breakthrough year for the nationalists was 2016 - with Brexit in Britain and victory for Donald Trump in the US. But the French election suggests that France and most of continental Europe will stay on the internationalist side of the line.

The contest between Marine Le Pen and Emmanuel Macron in the final round of the election on May 7 will be a classic contest between a nationalist and an internationalist. Ms Le Pen wants to pull France out of the European single currency, raise tariffs, strengthen frontier controls and crack down on immigration. Mr Macron is a fervent supporter of the EU and a believer in open trade and a liberal attitude to refugees.

The opinion polls - which accurately predicted that Mr Macron would narrowly beat Ms Le Pen in the first round of voting - now suggest that he will win a decisive victory in the final round of the election on May 7, gaining more than 60 per cent of the vote.

Of course, there is plenty that could still go wrong for him over the next two weeks. Ms Le Pen is a skilled television debater. Mr Macron is a wealthy ex- financier and former minister - who is vulnerable to being portrayed as a member of the out-of-touch elite. He could yet be tripped up by a scandal or a faux pas. But the strong likelihood is that the polls will be accurate and that the internationalist candidate, Mr Macron, will win a clear victory.

Because the Macron-Le Pen contest is part of an international ideological struggle, the outcome of the vote in France will be watched with intense interest in the rest of the world. The likely victory of Mr Macron will be greeted with delight in Brussels and Berlin, with disappointment in the Kremlin and the Oval Office - and with mixed feelings in London.

Ms Le Pen campaigned on similar themes to Mr Trump - although her language was considerably more moderate than that of the US president. (The National Front candidate, for example, has never proposed a Trump-style "Muslim ban" on all Muslims entering the country.) The Le Pen family enthusiastically endorsed Mr Trump for the US presidency; and the US president, in turn, has dropped heavy hints on Twitter that he supports Ms Le Pen in France - and expected her to win. But while Mr Trump himself will be disappointed by a Macron victory - his national security advisers, who hold less eccentric views than their boss, are likely to be relieved.

Russia's disappointment at a likely Macron victory will be much more straightforward. Mr Macron was the only leading candidate in the first round of voting to support a tough line against Putin's Russia. A Russian bank has also lent heavily to Le Pen's National Front - possibly as part of the Kremlin's investment in disarray in the EU.

The British reaction to a Macron victory will be a mixture of relief and apprehension. The government of Theresa May resists the characterisation of Brexit as a nationalist spasm - and emphasises the UK's continuing support for free trade and a strong EU. But the problem for Britain is that the EU itself clearly sees Brexit as a manifestation of nationalism within Europe that needs to be dealt with very firmly.

In that sense, a likely Macron victory is both good and bad news for the UK. Mr Macron represents the strong and united EU that the May government claims to want. The difficulty from London's point of view is that this strength and unity is likely to be expressed through a very tough line on Brexit - with a demand for a large, financial settlement from Britain and a resistance to any special deals for the UK, whether on free movement of people or financial services. A Le Pen victory, by contrast, would take Europe in new and dangerous directions - but could help to ease the narrow problem of Brexit, since there might no longer be an EU left to leave.

Setback for European Right

In the wider European context, Mr Macron's likely victory has to be seen in the context of setbacks for the nationalist right in recent elections in Austria and the Netherlands and their declining fortunes in Germany - where the populist Alternative for Germany party is falling back into single digits in opinion polls. A fresh mandate for Angela Merkel in September's German elections looks ever more likely. Nationalist parties have taken power in Poland and Hungary - but the original core of the EU is resisting the nationalist tide.

In Brussels, the prospect of a Macron victory will be greeted as an opportunity to restart the Franco-German motor that has traditionally powered the EU. But euphoria would be misplaced. When it comes to economic reform and European integration, Mr Macron says all the "right" things. Whether he can actually deliver them is another matter. Breaking France out of a cycle of low growth, high unemployment and rising debt has proved beyond a succession of ostensibly reformist presidents - including Jacques Chirac, Nicolas Sarkozy and even the current president, François Hollande. Mr Hollande failed despite appointing a dynamic young economy minister named Emmanuel Macron. Whatever happened to him? gideon.rachman@ft.com