JERUSALEM, Israel - Princeton scholar and best-selling author Bernard Lewis is considered by many to be the foremost authority on Islam in the world.
While he was in Jerusalem recently, Lewis gave an exclusive interview to CBN News Bureau Chief Chris Mitchell.
Click play to watch CBN News Chris Mitchell's report and Pat Robertson's analysis.
A Warning to America and the West
In his 90-plus years on Earth, Lewis has learned to take the long view of history. And in doing so, he has a warning for America and the West.
"The main message that I'm trying to communicate is that we are engaged in a struggle, comparable with the two great struggles of the twentieth century, against Nazism and Bolshevism," he said. "And it would improve our chances of winning if we understood who they are and who we are, and what it's all about.
Lewis says the struggle is between Islam and Christendom - two world views.
They both contend that theirs is the one true faith.
And while millions of secularists in America and Europe fail to see that they're actually involved in such a conflict, the nature of the fight is crystal clear for radical Islamists such as Osama bin Laden.
Lewis said, "Where you have two religions of the same self-perception, the same sense of mission, the same historical background in the same geographical area, conflict was inevitable."
That conflict, according to Lewis, "has been going on for more than 14 centuries: Crusade and counter-crusade, Jihad and counter-Jihad, conquest and re-conquest, sometimes one side winning and sometimes the other side winning."
An Age Old Battle
When bin Laden and his fellow radicals drove the Soviet Union out of Afghanistan in the early 1980s, people in the West saw a U.S. victory in the Cold War. But the Islamists saw it as the defeat of one of two major Christian powers.
"And now the only obstacle that remains for the worldwide triumph of Islam is the United States. So that is the next target and that is very clear," Lewis said.
Many Americans compare the war against radical Islam in Iraq and elsewhere with the Vietnam War. But Lewis says - that's the wrong way to look at it.
"The difference is that the Vietnamese did not follow us here except perhaps as refugees seeking asylum. These people will, and they were already here before this happened."
"If you look at their writings -- particularly at those of Osama bin Laden, but not only his -- it is perfectly clear that they see this as the final phase in the cosmic struggle between the true believers, the unbelievers and the misbelievers," Lewis said.
So, what are the stakes?
Lewis said, "The survival of our civilization."