Congress has to vote on bills for arms packages to our allies. The President has to sign it or not.
The catch is they always package stuff like this with stuff like “give water to Rwanda” so the President is forced to sign it otherwise he’s the “no water for Rwanda President”.
The best example of this lately is arming Israel. It’s packaged with probably the last ever military aid to Ukraine. They need it to literally not turn 30% of the continent of Europe into Russia. But means we gotta send shit to the assholes in Israel too. But it’s easier for people to just focus on the last part.