Dr Williams recently returned from the Holy Land

In an address inspired by a recent visit to the region, he said both Israelis and Palestinians feared being ignored as the world looked elsewhere.

He voiced concern over an "almost total absence" of belief in the region that a political solution can be found.

The archbishop delivered his sermon at Canterbury Cathedral in Kent.

He said he was inspired by a medical director in Bethlehem - the West Bank town where Christians believe Jesus was born - who told him: "The poorest deserve the best".

That slogan was underlined by the Christmas message, he said.

The poorest deserve the best - when you hear that, I wonder if you can take in just how revolutionary it is Dr Rowan Williams Sermon in full

Dr Williams told the congregation: "The tragedies of the Holy Land are not the problems of exotic barbarians far away; they are signs of the underlying tragedies that cripple all human life, individual and collective.

"Every wall we build to defend ourselves and keep out what may destroy us is also a wall that keeps us in and that will change us in ways we did not choose or want.

"Every human solution to fears and threats generates a new set of fears and threats."

Dr Williams, who was recently on a Christmas pilgrimage to the Holy Land with Cardinal Cormac Murphy-O'Connor, told the BBC the security barrier was causing problems, preventing people from going about their lives.

And his address will underline his fear for the Israelis and Palestinians.

"Both communities in their different ways dread - with good reason - a future in which they will be allowed to disappear while the world looks elsewhere.

"The beginning of some confidence in the possibility of a future is the assurance that there are enough people in the world committed to not looking away and pretending it isn't happening."

'Barriers to cohesion'

On Saturday, the archbishop accused the UK government of placing Christians in the Middle East at risk through its actions in Iraq.

We live in a culture that seeks to express itself as totally self-sufficient Cardinal Cormac Murphy-O'Connor England a 'needy land'

Meanwhile the Archbishop of York, Dr John Sentamu, has warned that multi-culturalism threatens cohesion.

In his Christmas Day sermon at York Minster, he said: "We, as citizens of this nation, must agree to build our dwelling tent together.

"I believe we should talk more about the common good and the values that have shaped this nation and less and less about multi-culturalism and cultural diversity.

And the head of the Catholic Church in England and Wales, Cardinal Cormac Murphy-O'Connor, said in his midnight Mass homily at Westminster Cathedral that England was undergoing a "truly radical break" with humanity's traditions.