Belloc was good on this - as were just about all writers and thinkers (including Popes and saints) until about 1950. I think that the coming of the Cold War and the fight against Communism made us back off on Islam, because we saw Islamists as also fighting against Communism. It's true, they were - but only because they wanted to install an even more ferocious tyranny. We, being historically ignorant like most Protestant/deist cultures and hence not aware of the centuries that the Church and, in fact, most of Catholic Europe had fought against the Muslims, simply skipped over this. And now we're paying the price.
Actually, in the early days, there were many people in the US who saw this, as browardchad showed us in that great post above. But the combination of short-sighted ignorance of the true objective of Islam, combined with PC, is what has made us unable to respond to this in our century. Well, we're starting, but until our leaders stop calling Islam the "Religion of Peace" and admit its true nature, we're going to be sitting ducks.
Did you read Pope Benedict's words to the Muslims the other day? He really called them - basically, he said that they were misleading their young people and it was up to them to correct it and teach in such a way that we could all live here together. But he never said that Islam was true, or valid, or the "Religion of Peace." He was about the most outspoken person I have seen, and did not flatter them.
Oops, of course you've read his words! I thought I was responding on a different thread! I normally read a bunch of threads at once and respond to several in different windows and of course I get confused...