He referred to the principle of the "Responsibility to Protect", a doctrine of global collective security still evolving since it was published in a Canadian-sponsored initiative in 2001 after the Rwanda genocide and war in former Yugoslavia.

The Pope said the principle had only recently been defined, but it was implicit in the origins of the UN. Referring to states' duties to their citizens, he said: "If states are unable to guarantee such protection, the international community must intervene with the juridical means provided in the United Nations Charter and in other international instruments."

There was also a responsibility to protect the weak. "I am thinking especially of those countries in Africa and other parts of the world which remain on the margins of authentic integral development and are therefore at risk of experiencing only the negative effects of globalisation," he said.

Referring to the dominant position of leading world powers, he said it was a paradox that the multilateral consensus continued to be in crisis because it was still subordinated to the decisions of a few.