If you want to understand why 6 million disaffected French voters gave their support to Marine Le Pen’s Front National candidates in the regional elections (and will do so again when they get the chance), you could do worse than contemplate the career of Laurent Fabius, the French foreign minister who chaired the 10-day summit on climate change in Paris.

Climate change campaigners, who worry most about the existential threat of global warming (I do myself), heaved a collective sigh of relief that leaders of 196 countries pulled off a cliffhanger agreement on Saturday night. Sceptics point out that key clauses are more aspirational than substantial; wishful hot air, we might say. Even supporters are wary.

I’m sure both perspectives are correct. As Monday’s Guardian editorial points out, multilateral international agreements are hard to reach, as David Cameron is finding out in his efforts to renegotiate Britain’s EU membership with just 27 colleagues. The stalled 2001 Doha trade talks resume (again) this week.

But they all remain a vital, if painfully rocky, road forward, especially at a time when technocratic internationalism, in vogue since the end of the cold war, is retreating before a rising tide of populist and xenophobic nationalism. The alternatives to Doha are regional pacts that carry clear dangers.

Step forward Fabius. You’ve never heard of him? I bet you have, though you can be forgiven for not remembering. Cast your mind back to the mid-80s when Margaret Thatcher was fighting the miners, Jeremy Corbyn was a new MP and Neil Kinnock was starting to expel assorted Trots from Labour’s tent, some the very same people now crawling back in.

In France, the then president, François Mitterrand, had just abandoned his experiment in “socialism in one country”, sacked the communists in his cabinet and embraced market reforms. His modernising prime minister, appointed to symbolise this compromise, was a 37-year-old technocrat called Laurent Fabius. He lasted 20 months until the Socialists lost the parliamentary elections in March 1986. You can read his CV here, but apart from the HIV-tainted blood scandal and the sinking of the Greenpeace ship Rainbow Warrior (both happened on his watch), there’s really no need.

Why not? Because he’s a very familiar French type, part of what they like to call the “republican elite” – clever men and women accelerated through an unashamedly elitist education system to the postgraduate colleges that dominate French public life and many corporations. These are the grandes écoles in and around Paris, where the brightest are inducted into the technocratic fraternité.

When I was at school in the dying days of the Fourth Republic of 1946-58 (De Gaulle replaced it after his return to power) there was a patronising joke about the French politician who fell asleep in a debate and woke to find he’d been prime minister three times. The Fifth Republic hasn’t been anything like as fragile since the EU partnership with Germany did wonders for French recovery and reform.

But the elite still get recycled in ways that Friends of the Earth ought to applaud. After flirting with rightwing Catholic nationalism before the second world war (where his role remains murkily ambiguous), Mitterrand first became a cabinet minister in 1947, held 11 jobs by 1958, many more posts over the coming decades and died shortly after leaving the presidency (1981-95) almost 50 years later.

In Britain, only William Gladstone and Winston Churchill, both exceptional men, can claim such longevity at the highest level. Ken Clarke, an MP since 1970, became a lowly government whip in 1972 and only gained cabinet rank when Mrs T could no longer ignore his ability in 1985, but kept it until 2014, a troublemaker to the end. But he is a genial freak of longevity. His peers are all long dead or, well, peers.

In France it’s pretty normal. Jaques Chirac, the president from 1995 to 2007, his comfortable background not so posh as Fabius’s but similarly educated in the grandes écoles, became an MP in 1967, a technocratic insider and protege of the then president, Georges Pompidou (don’t ask), who called him “my bulldozer”. A minister by 1968, when he helped negotiate a truce with rioting students, he became prime minister (1974-76), the mayor of Paris (1977-95) and so on.

Fabius is cut from similar cloth, except he swung to the left, not the right, and led the successful campaign to say no to the draft EU constitution in the 2005 referendum in France, the one that got Tony Blair off his Cameron-style hook. He lost the presidential nomination in 2007 to François Hollande’s old flame Ségolène Royal but was appointed foreign minister when the left finally won back the Élysée under Hollande in 2012.

As people, they are very different, but they have almost all gone through the same educational sausage machine to become what are known as “énarques” (as in École nationale d’administration), the folk who run the country. There is nothing like it here, certainly not an Oxford PPE, which is general studies by comparison with French postgrad rigour. Nothing much like it in the US either, though Harvard Law (the Obamas, the Clintons etc), the Kennedy School, Yale (the Bushes), Princeton and Stanford are pretty dominant. Money talks more than education in US politics, doesn’t it, Donald?

It’s government by this kind of highly familiar cast of elite politicians that so many French voters deem to have failed them in the globalising years. France remains a relatively good place to live in so many ways, but unemployment is stubbornly high at about 11% and has not fallen much since the banking crash and eurozone recession.

Economic insecurity feeds the anti-Muslim narrative much as it does in Britain and in Trumpland. As Simon Jenkins wittily put it, Trump’s xenophobic speeches sound like a frightened and insecure man playing eagerly into Osama bin Laden’s masterplan to make the west afraid.

Britain has plenty of troubled and insecure voters too, many with plenty to complain about. But Ukip is not the NF nor Trump, Nigel Farage is not Le Pen, father, daughter or niece Marion. It shies away from political dynasty more than the supposedly more egalitarian US. Ukip won 12.7% of the vote at the general election.

So Ukip is not a serious claimant to power, as Marine Le Pen still sees herself to be in 2017, despite the big parties ganging up to squeeze her out in the second round on Sunday. It did the trick, as it did in 2002 when Jean-Marie Le Pen faced Chirac in round two. But there was a price. Leftwing voters refused to rescue Chirac’s party twice and voted down the EU constitution in 2005.

It is not a card the mainstream can play forever, combining against the radical left and right, recycling familiar faces.

Imagine if junior ministers from the Clement Attlee or late Churchill era were still in control at Westminster 10 years ago, if cabinet grandees under Harold Wilson or Ted Heath had only just left the stage – or were still running the BBC or Rolls-Royce.

Our problem is the opposite, a tendency to overpromote young politicians and then spit them out when they are getting the experience to do the job better. Fabius will be 70 next year. If Marine Le Pen does well again in 2017 against Hollande, even if she doesn’t win, she may further poison the French political well.

In that case, even the well-meaning, but largely voluntary, climate change deal Fabius pulled together on Saturday night may be too late to do much good. In all sorts of ways, things are hotting up. Do you suppose anyone mentioned Rainbow Warrior to him in Paris?