The Muslim cleric was once a key Erdogan ally, but the Turkish strongman now views him as his archenemy. So much so that Erdogan accused Gülen of being the mastermind behind the military coup that rocked the country on Friday night. The cleric denied these allegations.
The Turkish president "will now implement a swift and forceful crackdown, which could easily escalate into an outright purge. Any member of the Turkish armed forces with even a tangential link to the Gulenist movement may face arrest," US-based think tank Stratfor noted.
The purge, like others before it, will adversely affect the Turkish Armed Forces, a once powerful institution that Erdogan has tried to weaken ever since he came to power.
"It will erode morale and lessen fighting cohesion. The arrest and imprisonment of combat leaders as well as quartermaster and military logistics administrators will increase disorganization and cause confusion among the ranks," the analysts detailed.
They further added that training schedules will likely be messed up "as routine exercises are postponed or canceled. Mistrust will spread. Planning for military operations will become more difficult as the government reforms its command and control structures."
Turkish authorities have cracked down on the Kurds in southeastern regions of the country since the months-long peace process collapsed last year. They are struggling to contain massive waves of refugees fleeing sectarian violence in Syria. Ankara has also been involved in the Syrian conflict and counterterrorism efforts in Iraq.
"This will make it difficult for Ankara to use the military as an instrument of policy and national strategy," Stratfor noted, adding that recovery from upcoming purges will take years that Turkey does not have.