One ex-Jihadi is not enough. From How a British Jihadi Saw the Light:
I had never expected to see such poverty in Saudi Arabia. Many African immigrants in Jeddah live in Karantina, a slum full of poverty, prostitution, and disease. Visiting Karantina, it dawned on me that many Muslims enjoyed a better lifestyle in non-Muslim Britain than they did in Muslim Saudi Arabia.
All my talk of ummah seemed so juvenile now. It was only in the comfort of Britain that Islamists could come out with such radical utopian slogans as one government, one ever-expanding country, for one Muslim nation. The racist reality of the Arab psyche would never accept black and white people as equal. Racism was an integral part of Saudi society. Even dark-skinned Arabs were considered inferior to their lighter-skinned cousins.
Two weeks after the terrorist attacks in London, a student in my class in Saudi Arabia said, "Teacher, I want to go London next month. I want bomb, big bomb in London, again. I want make jihad!" Another student shouted: "Me too! Me too!" Other students applauded. In protest I walked out of the classroom. My time in Saudi Arabia bolstered my conviction that an austere form of Islam (Wahhabism) married to a politicized Islam (Islamism) is wreaking havoc in the world. This anger-ridden ideology, an ideology I once advocated, is not only a threat to Islam and Muslims, but to the entire civilized world.