The international community is facing the same divisions today as in the 1930s over its responsibility to intervene to protect human rights, former foreign secretary David Miliband has warned.
At a fundraising dinner for the Anne Frank Trust, Miliband said the world had still not answered the question he said was posed by her diaries: "Whose responsibility is it to fight cruelty?"
He said: "The questions that dogged the 1930s about the responsibilities of states and the treatment of their own citizens, about the rights of other states to assert universal values and protect people from danger, those questions are as fraught today as they were in the 1930s.
"It's true that out of the horrors of the Holocaust came a new international settlement, embodied in the UN Convention on Human Rights.
"But today we can see that declaring rights is one thing. Enforcing them is a very different project.
"That's where the international community is pretty much split down the middle. There is no agreement and shared doctrine for the governance of our interdependent world.
"For every assertion of universal rights there is a counter assertion of national sovereignty. For every condemnation of governments which abuse power there is the loud cry 'It's none of your business''.
"That is the tragedy being played out in Syria and elsewhere today."
Miliband told the event, held at the Park Lane Hilton and marking Holocaust Memorial Day tomorrow, it was necessary to debate how "we can defend the rights of people whose aims we don't know, whose story we can only imagine, but in time might become as famous as Anne Frank.
"I honestly believe this is the next frontier in international law and international relations."