KIRKSVILLE, Missouri — In Britain and Australia, several Muslim medical doctors and engineers have been arrested following a series of failed car bombings. The arrest of these well-educated professionals, together with the Egyptian doctor Ayman al-Zawahiri's role as al-Qaida's deputy leader, raises questions that go far beyond disaffection among Muslims and the consequences of America's misadventures in the Middle East.

Doctors and engineers, after all, are professionals. They are well-off, established members of society, not marginal figures whom we might expect to be drawn to desperate acts of violence. Moreover, they come from a scientific background, and science is usually not associated with religious or political fanaticism.

Of course, only a minority of zealous Muslims espouses political violence, and only a tiny number of Muslim professionals set off bombs. Nevertheless, the presence of doctors and engineers in fundamentalist movements stands out. In fact, fundamentalist leaders often have professional backgrounds. Doctors who organize groups based on literalist readings of scripture and engineers who lead Islamist political parties are familiar figures throughout the Muslim world.