THE arrest of both leaders of an elected party is unprecedented for a member of the European Union. On September 28th the Greek government began a crackdown on Golden Dawn, a neo-Nazi party, which has 18 MPs in Greece’s 300-strong parliament. Among those put in handcuffs by counter-terrorism officers in bulletproof vests and balaclavas were Nikos Michaloliakos, leader of Golden Dawn, four other MPs and 14 party supporters. Mr Michaloliakos’s deputy, Christos Pappas, gave himself up to police a day later.Police and intelligence services have been gathering information on Golden Dawn’s supposed criminal activities for months. But it was the alleged murder of Pavlos Fyssas, an anti-fascist rapper, by a Golden Dawn supporter on September 18th that prompted the crackdown. Mr Fyssas’s killing sparked a national and international outcry and mass rallies against Golden Dawn. As protests against his party intensified, Mr Michaloliakos threatened to pull his lawmakers out of parliament, a move that could have forced a series of by-elections, destabilising Greece’s fragile coalition government.Under the…