Governments across the world should set up programmes for school pupils to interact with their peers from different countries and faiths to stop them being attracted by religious extremism, Tony Blair said.
The former prime minister warned in a speech to the counter-terrorism committee of the United Nations Security Council that education was "a security issue" which had to be addressed.
Mr Blair said young minds had to be exposed to "the other" so they were not won over by the "obscene perversion" of religion preached by extremists of all the major faiths.
He called for a widespread adoption of a initiative run by his Faith Foundation which "promotes cross-cultural dialogue" over the internet between students aged 12-17 in 20 countries.
"The extremists are able to organise because we are not organised," he said.
"This has to change. We have to educate. We have to educate the next generation of young people to have an open mind, to know about 'the other' and through that understanding to learn to respect them as equals."
Calling on the security council to recognise the issue, he said: "I advocate governments taking seriously their responsibility to educate young people to cultural acceptance and respect between people of different faiths and cultures.
"I would ask that each Government establishes at least a pilot programme in such inter-cultural understanding. Experiment with it. Experience it...
"Education in the 21st century is a security issue. In this sense we do know 'the answer'. It is to educate the next generation for the open mind. There is no better cause; nor one more urgent."