Back in 1985, the Social Democrats and Greens in the state of Hesse formed the first ever “red-green” government in German politics. When it collapsed less than two years later, it seemed destined to be a footnote in German political history. In fact, it turned out to be the prototype for a string of other “red-green” governments and ultimately for the national government under Gerhard Schröder in 1998. In the city-state of Hamburg the Christian Democrats and Greens are currently negotiating an agreement to form a “black-green” coalition under Ole von Beust that may eventually re-draw Germany’s political map in a similar way to that first “red-green” experiment. It also parallels other recent attempts elsewhere – for example by David Cameron in the UK and by former Bush speechwriter David Frum in the US – to formulate Green conservatism.

The counter-intuitive idea of a “black-green” coalition is becoming a reality right now partly because of the specific way that the arithmetic of power in German politics is changing. Since the emergence of the Greens as a political force in the eighties, German politics has been basically defined by two blocs: the Christian Democrats and the liberal Free Democrats on the right, and the Social Democrats and the Greens on the left. But since Oskar Lafontaine quit the Social Democrats and created a new left-wing party, which has now merged with the former East German communists, the PDS, that status quo has been shattered. In the new five-party system, it looks as if it will be increasingly difficult for either of the two traditional blocs to form a stable coalition – hence the need for new permutations. The Greens are particularly keen to reduce their dependence on the Social Democrats, who until now have been their only possible coalition partner.

The Christian Democrats and Greens have delighted in lambasting each other over the years – most famously in the so-called “battle of the bellies” between Joschka Fischer and Helmut Kohl in the Bundestag in the nineties. But their obvious political differences mask some deeper similarities that could, in the long-term, make a “black-green” coalition more viable, and more interesting, than it at first seems.

When the Green movement emerged out of the so-called “citizens’ initiatives” against nuclear power in the late seventies, it included renegade Christian Democrats like Herbert Gruhl as well as disillusioned Social Democrats like Petra Kelly. Nor, initially, was its ideology unambiguously left wing. In fact, it drew heavily on a right-wing, anti-modernist tradition in German politics that goes all the way back to the German Romantics. Although the Green party, which was formed in 1980, subsequently coalesced around traditionally left-wing principles, it remained a middle-class party that, unlike the Social Democrats, was not connected to organised labour.

One version of  “black-green” is therefore as a conservative coalition based on a centre-right, but nevertheless environmentally-conscious, economic policy and drawing on the etymological connection between conservation and conversatism. For a while in the nineties, it looked as if a conservative coalition of this kind might become a reality in the affluent southern German state of Baden-Württemberg. A pivotal figure then was Oswald Metzger, a Green über-realist who for a while was the Greens’ economic spokesperson who to the party’s left wing was a symbol of everything that was wrong with the party had cut itself off from its roots. Metzger finally left the party last November and now wants to join the Christian Democrats.

There is, however, a second, perhaps even more intriguing possible version of “black-green” centred around libertarian conservatism. The German Christian Democrats never had a Reagan or Thatcher and remain a much more statist – or in German political terms, “social” – party than the American Republicans or the British Conservatives. One of the very few genuine libertarian conservatives in Germany is Thomas Schmid, the editor of the newspaper Die Welt, who was arguing for a “black-green” coalition that would combine economic and social liberalism back in the mid-eighties.

Along with Joschka Fischer and Dany Cohn-Bendit, Schmid was a member of Revolutionary Struggle, a radical left-wing group that fought the police on the streets of Frankfurt in the 1970s. He joined the Greens and now says he is neither left-wing nor right-wing but simply “liberal” – both economic and social terms. What the Christian Democrats and the Greens have in common, he says, is a “certain scepticism about state intervention”. One of the German Greens’ four founding principles is grass roots democracy – which chimes with many conservatives’ views about devolving power to the local level.

Until recently, a major stumbling block to this kind of libertarian conservative alliance was the Christian Democrats’ periodical swings to the right in social policy and in particular on immigration. That tendency was epitomised by Roland Koch, who rose to prominence in 1999 with a campaign against immigration that got him elected as prime minister of Hesse – a Social Democrat heartland – and was for a while considered a possible future Christian Democrat chancellor.

But when Koch tried to run a similar anti-immigrant campaign in January, voters kicked him out of office – a sign, perhaps, that both the Christian Democrats and Germany as a whole are becoming less xenophobic. Ole von Beust, who is gay and belongs to the more progressive, tolerant wing of the party, had much greater success in the Hamburg election a month later. If the Christian Democrats do indeed become more socially liberal (still a big if), that will make coalitions based around libertarian conversatism an increasingly viable option in Germany – and, perhaps, beyond.

See also my brief piece on this in this month’s Prospect.