Making a deal encompassing the whole world is unlikely to be easy. But next month's special United Nations summit had seemed a propitious moment for a North-South grand bargain on development and security and on how to pursue these priorities through a reformed UN. It would, essentially, involve rich countries doing more to remove the poverty and disease that poor countries see as the main threat to their existence, while the latter would help counter the terrorism and weapons proliferation that most worry the former.

Yet, as of today, there is nothing in the way of an agreed text for the 170 world leaders gathering in New York in three weeks' time to sign.