A military that appeared, on the surface, to be largely under the thumb of Mr. Erdogan is clearly riven with divisions so severe that the chief of staff appears to have been be detained while lower-level officers put tanks on the streets of Istanbul and the air force over Ankara, the capital.
Mr. Erdogan has plenty of enemies, eager to see him weakened or removed from power. Among them are Egypt’s president, Abdel Fattah el-Sisi, who took power in a coup three years ago. The Russians, led by President Vladimir V. Putin, have tense relations with Mr. Erdogan, who has helped try to depose President Bashar al-Assad of Syria. And Mr. Assad himself would likely be both pleased and amazed if he held onto power longer than Mr. Erdogan.