LONDON — George W. Bush's visit to London this week will be historic for at least two reasons. He will be the first U.S. president to come to Britain on a state visit. He will also observe a bizarre political marriage: one between the remnants of the Marxist-Leninist Left and militant Islamists. Negotiated over the past two years, the "wedding," will be celebrated in a mass demonstration against Bush's visit. The demonstration is organized by a shadowy group called "Stop the War Coalition," part of the Hate-America-International, which has orchestrated a number of street "events" in support of the Taliban...