What can come of such genuine exchanges of ideas? Who knows? But when oceans no longer protect us from foreign terrorists, neither is it so easy to block utterly at least the trickle of new ideas.
"The whole exchange has had a tremendous impact," says Hassan Mneimneh, co-director of the Iraq Research and Documentation Project at Harvard. "It is actually a catalyst for intra-Islamic debate. It is hard to find an intellectual in the Middle East who is not aware of the exchange of letters."
How influential has the exchange been? Influential enough that Saudi Arabia recently paid it the ultimate consequence: banning a London newspaper that carried the Americans' latest response.
"The Saudi government doesn't like this debate, particularly because the people who wrote the Saudi response are mostly Wahhabi conservatives and fundamentalists," Ali Al-Ahmed, director of the Saudi Institute, a Virginia-based nonprofit organization that promotes democracy and civil society in Saudi Arabia, told The Washington Post. "They don't want the dialogue, and I think the reason is they don't want nongovernment elements to have a voice internationally."
But if the war of ideas is what matters, then more such civil, respectful, frank exchanges between nongovernments (aka citizens) are going to be key.