Much has been written about the world becoming multipolar, but nobody seems to be able to tell what such a world would actually look like. After the spectacular nuclear deal between Turkey, Brazil and Iran, the picture becomes a little clearer and it seems that the P5, the mighty five permanent members of the Security Council, will have to share some of the world’s attention.

Twenty years after the collapse of the Soviet Union the world is only slowly adjusting to the new realities, while the old political structures have remained pretty much the same. The reform of the United Nations and its Security Council is dying silently in numerous committees, much to the frustration not only of countries like Germany and Japan, which have been hoping to join the exclusive club, but also of the emerging economies from the South, which have long felt excluded.

But it is not only about formal representation. I believe in order to understand the reluctance of countries like Turkey and Brazil to join the efforts of the United States and Europe in pressuring Iran to give up its nuclear programme requires an appreciation of their sentiment of exclusion and humiliation. From the revolutionary liberation movements to the dependency theory of the sixties and seventies, the countries of the South have created their own narrative on the reasons for their underdevelopment and political dependency on the West.

Whether you agree with it or not, without understanding this narrative of exclusion, western politicians will hardly learn to comprehend why leaders like Hugo Chavez or Robert Mugabe still enjoy solidarity among a vast group of developing countries, regardless of their political conduct. The same may unfortunately also be true for Iran’s president Ahmadinejad.

But the narrative, of course, is only one part of the picture. With the economic success of the emerging economies, a new political self-consciousness and the determination to defend their interests has emerged. The most striking example is Brazil, which opened 30 embassies around the world in the last years, enhancing her influence mostly in Africa. Brazil today is defining herself as a leading voice of the South, and the United States and its European allies better take her demands seriously. While some pundits look with scepticism at Brazil and regard her policies towards Venezuela and Iran as a pet-project of President Lula’s centre left workers party, it is important to stress that Brazil’s foreign policy is based on a broad bipartisan consensus. Foreign minister Amorim, who also served under Lula’s predecessor Cardoso, is the embodiment of this new consensus of the Brazilian elite and its highly skilled foreign service.

The proliferation of new actors on the world stage is causing concern in western capitals and has given birth to a literature about the dangerous rising stars from the East and South, which has not always contributed to a rational debate. Nevertheless, I believe the left should embrace a more diverse UN, a demand that has been on the agenda of the political left in the West for decades now.

But the nuclear deal with Ahmadinejad also made clear that new actors do not automatically deliver convincing results. A closer look at the content of the nuclear deal with Iran indicates that Ankara and Brasilia failed to address the tricky questions, while Tehran made no commitment at all to give up its nuclear ambitions. That neither Lula nor Erdogan mentioned the ongoing violation of UN resolutions by Iran is not good news for the credibility of the United Nations.

The Cold War is over and the brave new world requires a new kind of leadership, and this is especially true for the developed countries in the West. But if countries like Brazil want to assume their legitimate role on the world stage, they will have to share responsibilities. Given the reactions after the announcement of the deal in Tehran, it seems quiet obvious that the US has underestimated Brazil’s and Turkey’s dedication to carry out this mission; and the images of the signing ceremony in Tehran indicate a rare moment of triumphalism over the establishment. But is a deal a good deal only because a country of the South has brokered it?