Mythical Muslim Moderates?

No, they're not mythical.

Muslims exist who wouldn't, themselves, detonate a suicide bomb. These are probably a majority of the group.

Muslims also exist who'd actually notify the authorities if they knew of, or suspected, an impending terrorist attack. Are these a majority, or are we now talking about a minority of the group?

Unfortunately, the jury's still out on this question. Only the Muslim community can answer that question for us, and they've not yet provided us with an answer we can fully understand.

Ms Nirenstein notes the following:

So, we cannot count on "moderate" Arabs, not even on the group of youngsters that I meet later, the girls dressed just like ours: They repeat to me, still with a smart little face, "It cannot be a Muslim, it's certainly the Israelis and the Americans." The dream palace of the Arab, after the terrorist attack in Sharm, just like the thousands of attacks in Iraq and in Israel, is still there; the summer camps of Hamas still teach that it's good to kill the Jews; several madrassas work full time as centers of recruitment; the television broadcasts an "analysis" that charges the Mossad and the CIA with mass murders. The dictators of the Arab countries, in this case Mr. Mubarak, don't let Khaled know who the guys that cut their legs are. So, Khaled can be as "moderate" as we want, but so long as that fascist culture of hate is there, we can count only on ourselves.