BRITISH AUTHORITIES have been slow to acknowledge openly the Pakistani-Muslim background of the suspects arrested in the mass terror conspiracy that brought chaos to British and American airports Thursday. At first, official sources in the United Kingdom would confirm only that they were working with "the South Asian community" on the case; then it was disclosed that the Pakistani government was involved in the investigation. This reticence in naming the focus of so significant a terrorism inquiry is a symptom of the larger problems of Islam in Britain, and of "Euro-Islam" more generally. Put plainly, Pakistani Sunnis in Britain--more than...