Congress has approved legislation that would prevent any president from withdrawing the United States from NATO without approval from the Senate or an Act of Congress. The measure, spearheaded by Sens. Tim Kaine (D-Va.) and Marco Rubio (R-Fla.), was included in the annual National Defense Authorization Act, which passed out of the House on Thursday and is expected to be signed by President Biden.
No, you are missing the entire point of three branches of government. They are there as a check and balance of power to the others. They are literally supposed to stop the other branches from overstepping.
It’s been established that the president is in charge of foreign treaties. So it is congress that is overstepping here.