Which policy do you think is more effective LBJ's, or Carter's, or do you think the USA should simply stay out of other countries' buisness? One sentence

I believe that a mix of both LBJ's and Carter's policies, focusing on diplomacy and non-intervention, would be the most effective approach for the USA in dealing with other countries.

you can only choose one

I would choose Carter's policy of diplomacy and non-intervention as I believe it promotes peaceful resolutions and respects the sovereignty of other nations.