San Francisco is 3rd of 6 places that changed the world

In San Francisco's opera house exactly 60 years ago, the United Nations was founded. Led by the victorious Second World War allies, 50 countries met to set up an organisation which it was hoped would prevent the great wars of the past century from happening again. But do failures in Rwanda, Srebrenica and Iraq suggest the institution is no longer able to cope with the conflicts of the modern world? Will countries ever put the greater good above their own interests? Gavin Esler explores the past and the future of the UN.