Talk of the Nationals leaving the Coalition — as they threatened to do yesterday — is perpetual, dating back to their time as Country members — damn that doesn’t work in the plural — and their occasional partnerships with Labor, notably in Victoria in the 50s.

As with the behaviour of most co-dependent spouses, it is mostly flounce and theatrical suitcase packing and the occasional half-hearted suicide attempt. If you want to know what being a Liberal party leader of the Coalition is like, go out with an actress.

But as time moves on, that ritualised threat is acquiring more oomph for the simple reason that the whole political ground on which the Coalition is based is splitting in several different directions.

Famously, the Coalition has always been an obvious stitch-up between a right-wing pro business party, and a bunch of agrarian socialists happy to impose raw capitalism on the urban working class. That could actually bumble along, as long as the economy was at the centre of political life, and everything else was marginal.

But now it ain’t. The environment is, for the simple reason that everyone understands, at some level, that the environment is not just this or that Potoroo species, but the basis on which life is possible. The people at the sharp end of this are rural Australians, their whole communities under threat from both environment and economy.

Whether it’s the global competition to crops that cannot compete on the world market without subsidies — but upon which whole communities rely — the increasing conflict between mining and agriculture, as in the black earth country of NSW that Billiton wants to dig up, salination, water supply, the madness of a century of thirsty crops — rice and cotton — on a dry continent, both Nationals and rural Liberals are faced with the unpalatable truth — that they cannot regard nature as a “given”, an apolitical category of life whose solidity can be assumed.

Nature is now culture, and politics, in the sense that our survival and prosperity depends on the continuous reconstruction, restoration and management.

To think that way is to consider nature as a dynamic system of many intersecting levels of action, acted on by, and acting on, humans. In other words, Green politics. No matter how they wiggle out of it, representatives of rural politics are in Green politics, because the screw-up of the environment has got so bad that it’s vomiting back on the people who depend on it.

However, culturally, in the establishment of their identity, rural Australia depended on precisely not acknowledging that truth for a long time. They inherited a Judeo-Christian, promethean, idea that you made meaning by taming the wild earth, making it work for you. To have to face up to the fact that a salinated river cannot simply be worked around, but must be fixed, or that miners and farmers are not on the same side, that no matter how hard you work there may be no market for crops grown cheaper elsewhere, is not only galling — it directly attacks a sense of who people are.

The first reaction to a crisis of identity is hysteria, and under that heading file both Pauline Hanson and Barnaby Joyce. The latter may be more cogent than la Hanson but his mix of climate change scepticism, bursts of social conservatism — supporting student union funding of sports only, because “ratbags” would take over all the other services — and the whole plain-speaking act is the last gasp of a very old politics, in which a whole range of attitudes could be expressed as a single passage. There ain’t no such package no how no way anymore.

The Nationals have a road back from extinction, and it’s to leave the Coalition and offer the Liberals looser support in a government scenario based on a range of tougher conditions that emphasise the distinctive conditions and challenges of rural Australia — an agenda which demands a mix of free market politics, protectionism, social democracy and some hard Green thinking.

They should then challenge Libs in rural/regional seats precisely on those differences — and/or persuade Libs such as Bill Heffernan to join them. Heffernan’s eye-popping interview on Lateline the other night made clear that the fissure in right politics doesn’t run through the parties, it runs through the individual pollies — someone like Heffernan sounds identical to Bob Brown when he gets onto topics he knows something about, like water supply and global agriculture.

The Nationals could then explore policy-by-policy links with the Greens, since their respective platforms on a whole range of issues sound increasingly similar anyway. Years ago the canny hook up between the late Rick Farley at the NFF and Philip Toyne at the ACF created a category busting alliance that prompted a giant leap in Australian environmental policy and practice in a dozen different fields.

It’s time for that to happen again, but if the Greens want it they have to change too, and wind up the whole watermelon party routine — green outside, red in. Their championing of human rights and being the only party early and often to talk back to China is admirable, but that and their whole left liberal baggage of euthanasia, abortion policy etc, is the mirror of the Nats’ dilemma — a take it or leave it inner urban new left package delivered late from the 80s.

The Greens should simply dump their social policy per se, take it off the books, and proclaim that on a whole range of issues these are simply conscience votes. It should be possible to imagine in the near future, a Greens senator who is, reasonably and constructively, anti-euthanasia, opposed to drug decriminalisation and anti-abortion.

If the Greens truly believe that the whole ecosystem is under imminent threat then they should redefine these other issues as outside their programmatic politics.

On that basis, a new and more creative politics is possible — one where people can acknowledge their differences while working on solid common ground, outside of zombie categories. But it will take real leadership from both parties to achieve it.

I’m confident the Greens have it if they want to. Can the Nats produce something other than carnival acts and invisible men?