UNITED NATIONS — First, the government soldiers made sure no food could get into rebel-held towns. Then, government planes bombed what health centers remained in those towns, making sure that those who got sick from hunger had no medical care to save them.

That is the harrowing picture painted by the latest report of the United Nations Commission of Inquiry on the war in Syria. The report, released Monday, chronicles a series of attacks on health care centers by government forces and the Islamic State, and it says the “deliberate destruction of health care infrastructure” was responsible for driving up deaths and permanent disabilities.

To follow the commission’s work in Syria — it has written 11 reports since August 2011 — is to witness how blatantly the laws of war have been broken, with no prospects of accountability.

The commission flatly asserts in the latest report that “war crimes are rampant” by government forces and their armed rivals, and for the first time it sharply points to the very countries that are bargaining over a peace deal for fueling the violence.