Turkish President Recep Tayyip Erdogan has publicly accused his bitter rival Mr Fethullah Gulen, a reclusive cleric who has been in self-imposed exile in the United States, of organising a failed coup over the weekend, and called on the American authorities to arrest and extradite him. Mr Gulen has denied the allegation and in turn suggested that Mr Erdogan might have staged the putsch himself, adding that he would obey any extradition ruling from the US. Here, Dr James Dorsey of the S. Rajaratnam School of International Studies looks at how the former allies became enemies, as well as Mr Gulen’s influence on Turkey.

Believers say he preaches a new, modern form of Islam. Critics charge he is a power-hungry wolf in sheep’s clothing preparing to convert secular Turkey into an Islamic republic; a conspirator who has created a state within the state and attempted this weekend to topple democratically elected Turkish President Recep Tayyip Erdogan in a failed military coup.

That was not how past Turkish governments — or, for that matter, Mr Erdogan in his first eight years as Prime Minister — saw Mr Fethullah Gulen, the leader of one of the world’s largest and wealthiest Islamic movements.