They were the leading, and most successful, edge of a worldwide movement of radical Islamists with cells in every continent, with worldwide financial and theological support, with a massive media and propaganda arm, and with an archipelago of local sympathizers, as in northwest Pakistan, who protect and guard them.
Krauthammer goes on to estimate that Islamism is espoused by a grand total of 7% of Muslims worldwide. That's enough, apparently, to entitle Islamophobes to regard all Muslims with suspicion and perceive any Islamic presence near "Ground Zero" as an insult.
Ground Zero is the site of the most lethal attack of that worldwide movement, which consists entirely of Muslims, acts in the name of Islam and is deeply embedded in the Muslim world. These are regrettable facts, but facts they are. And that is why putting up a monument to Islam in this place is not just insensitive but provocative.
Monument? That sounds suspiciously like the opinion of discredited Tea Party mouthpiece Mark Williams, who described the proposed mosque/community center as some sort of tribute to the 2001 terrorists. That kind of rhetoric is pretty provocative in its own right. In any event, Krauthammer's syllogism fails because it doesn't follow that anyone needs to be provoked, or should have their sensitivity offended, by a "monument" to a notoriously decentralized religion, one which has no central authority to command all the faithful and therefore cannot be said to have initiated or endorsed Atta's attacks.
Krauthammer currently believes that Pearl Harbor is his winning analogy in arguments with mosque supporters. He asserts that "the people of Japan today would not think of planting their flag at Pearl Harbor, despite the fact that no Japanese under the age of 85 has any possible responsibility for that infamy." But when Stephen Cohen explained why the analogy failed -- because Atta's terrorists were not agents of any central Islamic authority in the way that the Pearl Harbor attackers were agents of the Japanese Empire -- Krauthammer replied in the manner quoted above.
None of the analogies to which Krauthammer and fellow Islamophobes resort will win an argument, however, because the argument in favor of the mosque is that an Islamophobic expression of grief over the 2001 attacks is irrational. It may sound mean of me to say this, but it would be just as irrational for Americans over the age of 85 to continue to hate Japan for what happened at Pearl Harbor nearly 70 years ago, and it was just as irrational for Jewish protesters to see some sort of anti-Semitic intent in the nunnery at Auschwitz, to bring back another favorite analogy of the moment. Grief does not confer an entitlement to be irrational. By writing this I may risk the charge of being insensitive to grief itself, but let me raise the stakes by questioning the sincerity of the grief. Is this really about grief at all, or is it about grief conferring a right to hate? No one would be offended by the erection of a mosque if they didn't hate Islam already. That's Islamophobia, and that's the bottom line.