The inspectors, instructed to investigate the attack but not to assign blame, nonetheless listed the precise compass directions of flight for two rocket strikes that appeared to lead back toward the government’s elite redoubt in Damascus, Mount Qasioun, which overlooks and protects neighborhoods and Mr. Assad’s presidential palace and where his Republican Guard and the army’s powerful Fourth Division are entrenched.

“It is the center of gravity of the regime,” said Elias Hanna, a retired general in the Lebanese Army and a lecturer on strategy and geopolitics at the American University of Beirut. “It is the core of the regime.”

In presenting the data concerning two rocket strikes — the significance of which was not commented upon by the United Nations itself — the report provides a stronger indication than the public statements of intelligence services of the United States, France or Britain that the Syrian military not only carried out the attack, but apparently did so brazenly, firing from the same neighborhoods or ridges from which it has been firing high-explosive conventional munitions for much of the war.