How would abandoning NATO and our Allies strengthen us?

I do not like Trump, but I would like to think most conservatives that voted for him voted for him for the same reasons I voted for Kamala, because they think he will make our country stronger. I have been trying to give him the benefit of the doubt but this blows my mind. I can’t see any world in where this doesn’t leave the Us weaker than it’s been since pre 50s