The German social democrat Bebel wisely called anti-Semitism "the socialism of fools". This bracing, combative account of its modern resurgence finds much nasty new evidence among pro-Islamist leftists.
Yet the author would agree that a hatred of Jews still counts as the conservatism of morons too. MacShane, as a Labour MP, turns his unblinking gaze on the left – "my political community" - in order to guard against the spread of bigotry under the cloak of pro-Palestinian or anti-war activism.
However, events in the European parliament show that the foul old swamp of reactionary prejudice that bred anti-Semitism still sucks in right-wing idiots. Some of the polemic here has a scattershot air that will date. But the warning to progressives - to purge their thinking of all trace of a vile ideology – rings out clear as a bell.