The post-crisis model of development must not be reduced to a reform of finance prudential rules and supervision, even an ambitious one. Due to its common character with the Thirties, present crisis needs a more Rooseveltian New Deal between Capital and Labour. But this crisis is not a mere reproduction of the Great Depression. As in the "Ancient Regime" crises, the "Humankind/Nature" nexus is at the core of the problem, this time in a structural way. No New Deal could lead to a sustainable regime if it is not a Green Deal. The Green Deal entails dramatic changes from the Liberal-Productivist model, but it could not be a revival of Good Old Fordism or Welfare State (even at world level), if by "Welfare State" we considerer a mere redistributive State. Ecological sustainability is now a decisive character required by any regime. Some sketches of the Green Model of development already appears: ・A technological paradigm input-saving, labourintensive, based on industrious, skilled forms of work with a negotiated involvement of workers. ・A regime of accumulation distributing gains in productivity more generously to wage-owners, in priority under the form of free time, and driven by semi-public demand of green investment and common goods. ・A mode of regulation based on more stable capital-labour relations, the development of Social and Solidarity Sector, with incentive envi ronmental planning through Eco tax and tradable permits, and creation of money supply directly dedicated to green investments, ・An international configuration based on cooperation between old an emerging powers in the promotion of social and environmental common rules, probably organised through continental-size economic and political blocks, with a super Marshall Plan towards LDC. Some will think this sketch a fairy tale. Let us remember that Karl Polanyi, who identified correctly the Great Depression as a collapse of the "selfregulating market" that could only destroy Nature, Labour and Machines, correctly forecast that the alternative would be more interventionist. But interventionism could take three forms: fascist, Stalinist or social-democratic. Actually, in the third year after Black Monday, recessive economic liberalism remained untouched, with Hoover, with Laval... In the last years of the decade, interventionism had won everywhere, but in general under the most totalitarian forms, fascism and Stalinism. Only the anti-fascist victory permitted the triumph of social democratic market economy in the West, when Stalinism progressed in the east. A direct jump to a Green New Deal is possible, avoiding the tragic detour of the Forties. But the demonstration of its consistency is not sufficient, for the lack of confidence and the weight of inplace interests will oppose to it. A Green Model is necessary, but a democratic way to this achievement will need as more political subtlety than scientific demonstration. The basis of any step is: building confidence in the possibi lity to change things, together, through cooperation.