As on previous Saturdays in the past six months, there were two marches taking place in London yesterday. The first, a gathering of tens of thousands of full-throated, flag-waving supporters of an immediate ceasefire in Gaza gathered at Hyde Park Corner at noon, and shuffled peaceably and patiently in the sunshine in the direction of the American embassy at Vauxhall, over the river. The second march was taking place mostly in the imaginations of right-wing commentators and politicians who increasingly choose to see these displays of solidarity with the Palestinian cause only as a provocation and a threat. Following the...