The White House issued a detailed list of the use of chemical weapons in Syria, blaming Bashar al-Assad’s regime for using them against his own people.

“The United States assesses with confidence that the Syrian regime used chemical weapons in the eastern Damascus suburb of Duma on April 7, 2018, killing dozens of men, women, and children, and severely injuring hundreds more,” the memo read.

The lengthy memo was released after President Donald Trump announced precision strikes against military targets in Syria.

The White House described a pattern of behavior from the Assad regime to “terrorize and subdue” civilians with the use of chemical weapons, citing 15 incidents since June of 2017.

“Assad is collectively punishing his own people as a warning against further rebellion,” the memo read.

The White House explained that Syria was repeatedly using chemical weapons to “compensate for its lack of military manpower,” which required a military response.

“This history clearly illustrates the Assad regime’s consistent use of chemical weapons,” the memo read. “Such use will continue until the costs to the regime of using these weapons outweigh any idea that they may provide military advantages.”

Secretary of Defense Jim Mattis briefed reporters at the Pentagon, one hour after President Trump announced his decision to launch attacks on Syria.

“I am confident the Syrian regime conducted a chemical attack on innocent people in this last week,” he said in response to a question. “Yes. Absolutely confident of it.”