The world must take a stand against Islamic fundamentalism and support the principles of religious freedom and open economies, former British Prime Minister Tony Blair, the Quartet representative to the Middle East, was to say Wednesday in a speech at the Bloomberg London H.

In the speech, the text of which was released early, Blair also argues the fate of Israel "remains absolutely core to the region and the world" and that U.S. Secretary of State John Kerry was right to invest so much effort into attempting to forge an Israeli-Palestinian peace.

"There is a titanic struggle going on within the region between those who want the region to embrace the modern world – politically, socially and economically – and those who instead want to create a politics of religious difference and exclusivity," says Blair. "This is what, irrespective of the problems on the Israeli side, divides Palestinian politics and constrains their leadership."

"We have to take sides," says Blair. He is calling on the world to commit to the Middle East and engage in it, specifying that while this does not necessarily mean military involvement, "it does mean stirring ourselves."

"We have to elevate the issue of religious extremism to the top of the agenda," says Blair. "All over the world the challenge of defeating this ideology requires active and sustained engagement."

Blair says the threat of radical Islam, an ideology he says is "incompatible with the modern world" and "distorts and warps Islam's true message," is growing.

"It is spreading across the world," says Blair. "It is destabilizing communities and even nations. It is undermining the possibility of peaceful coexistence in an era of globalization. And in the face of this threat we seem curiously reluctant to acknowledge it and powerless to counter it effectively."

Israel, says Blair, is "in the center of this maelstrom."

"Its alliance with the USA, its partnership with leading countries of Europe, and the fact that it is a Western democracy, mean that its fate is never going to be a matter of indifference," says Blair. "Were the Israelis to be pulled into a regional conflict, there is no realistic way that the world could or would want to shrug it off. For the moment, Israel has successfully stayed aloof from the storm around it. But the one thing the last few years has taught us (and them) is that we can expect the unexpected."

Blair says the Middle East peace process, which "still seems as intractable as ever," is similar to recent crises in Iraq, Afghanistan, Libya and Syria in that the explanation for all these is the conflict between two ideologies.

Kerry was right to put "immense effort" into attempting to make the Israeli-Palestinian peace process work, says Blair.

"It remains absolutely core to the region and the world," he says. "Not because the Israeli-Palestinian conflict is the cause of our problems. But because solving it would be such a victory for the very forces we should support."

Rather than the Israeli-Palestinian conflict being the key to resolving the larger problems of the Middle East, it may be that "we're about to enter a new phase where solving the region's problems [is] a critical part of solving the Israeli-Palestinian issue," he says.

Either way, "Kerry’s commitment has not been in vain," says Blair. "He has put himself in an immensely powerful position to drive this forward by virtue of that commitment. He needs our support in doing so."

