Without bothering to go through Congress, the president signed an executive order this week vowing to defend Qatar in the event of a foreign attack.

Trump’s new executive order added that the U.S. was prepared to take “all lawful and appropriate measures — including diplomatic, economic and, if necessary, military — to defend the interests of the United States and the State of Qatar.”

Part of what makes the NATO charter so important is the security guarantee: An attack against any member nation is seen as an attack on every member nation.