This is less surprising if you first understand that in mainstream Islamic teachings, the world is divided into "the house of Islam" and "the house of war." That is, part of the world is Islamic and the other part has yet to brought into the light with Allah's holy law (Sharia).
And since relations with the non-Islamic part of the world exists in a state of war, then deceit is an appropriate strategy, used by all military commanders since the beginning of warfare.
As Raymond Ibrahim wrote, the Quranic verses 3:28 and 16:106, as well as Muhammad’s famous assertion, “War is deceit,” have all led to the formulation of a number of doctrines of "taqiyya.” And this is not an obscure point of theology. It is being practiced today by devout Muslims. See some examples of taqiyya caught on tape.
In the book, Terrorist Hunter: The Extraordinary Story of a Woman Who Went Undercover to Infiltrate the Radical Islamic Groups Operating in America, Rita Katz wrote about being at an IAP conference in Chicago. IAP is the Islamic Association for Palestine. There were lots of booths at the conference for "charitable" organizations, and at one of these booths, Katz met a man she already knew about: Muhammad Salah. She pretended she didn't know who he was, and he introduced himself as a "Muslim human rights activist."
Katz, a non-Muslim woman dressed as a Muslim, wrote, "He was small, thin, nearly bald. Totally harmless looking." He told her these conferences were so important because "we can teach you about the oppression and sufferings of Muslims in America and all over the world."
Then he told Katz his story. He had been a Palestinian with an American citizenship, a used-car salesman, working in Chicago when he went to Israel to "visit family and friends." But in Israel he was arrested by the Israeli authorities and thrown into prison for five years!
Katz looked appropriately appalled and asked why in heaven's name would they put him in prison? "Because the Israelis oppress innocent Palestinians," he said. "And do you know what is the most shocking part? When I returned to the U.S., after I was tortured and I thought I was going to die in that prison, the Americans placed me under investigation and froze my assets! Me, an innocent citizen, a car dealer, a family man, father of five!"
To any other kafir this probably would have been a convincing story. The poor, oppressed Muslim! It's just wrong to treat people that way. Those Israelis must be very cruel. Those Americans are so oppressive to Muslims!
But Katz was not an ordinary kafir. She researched people like Salah for a living. She knew all about him. This frail, innocent-looking man was the leader of the worldwide military wing of Hamas, a brutal terrorist organization! When he was arrested in Israel he had a hundred thousand dollars in cash on him. In his testimony, he admitted the money was supposed to go to "members of Hamas's military wing." He displayed detailed inside knowledge of Hamas's structure and funding, and his testimony was later used as evidence in the New York trial of Musa Abu Marzook, the leader of the political bureau of Hamas (and the man who had appointed Salah to his position as leader of the military wing). Katz writes:
"Salah disclosed (in his testimony) that he'd been authorized by Marzook to recruit individuals for training in the uses of explosives to fight in the 'holy war.' In the United States, Salah began training ten such recruits, three of whom were chosen to carry out attacks. In addition to supervising the building of bombs, explosives, and remote detonation devices, Salah was instructed by Marzook to develop biological and chemical weapons for Hamas."When Nasser Hidmi was caught trying to detonate a bomb in Israel, he said he had been chosen by none other than the poor, innocent, abused, oppressed Muslim, Muhammad Salah.
This is an example of the principle of religious deception in action.
The use of taqiyya is the main reason most non-Muslims are so confused about the real nature of Islam — they are constantly being intentionally deceived by orthodox Muslims. But once you know about it, the jig is up. You are much less easily deceived.