IN ANOTHER era, tanks might now be on the streets of Ankara and Istanbul. Over the past year Turkey has seen a crackdown on protests, corruption scandals, a purge of the police and judiciary, paranoid talk of foreign plots and fifth columns, an economic slowdown and more attempts to Islamicise society. Given this turmoil, Turkey’s soldiers would no doubt be tempted to sweep aside the failed politicians (as they have done four times in the past). That the generals have remained in barracks—or, in many cases, in jail—is a sign of democratic progress. But after years of strong growth and political reform, Turkey is sliding backwards, with more than a whiff of authoritarianism about the prime minister, Recep Tayyip Erdogan, whose Islamist-flavoured AK party has been in power since November 2002.Mr Erdogan claims that a wave of arrests on December 17th, as part of an anti-corruption investigation that included the sons of three cabinet ministers, was a more grievous assault on democracy than any past coup. Indeed, he is making overtures to the same generals whom he put behind bars. His enemy now is his former ally, Fethullah Gulen, Turkey’s most influential cleric, who…