I don't think it would be a good idea for the US to reduce their international activities, but I would balance the measures by doing them a bit. The US military costs as much as the 14 second-biggest militaries of this world together. But it's time to end the misconception that the US has its pockets full of "candy bars" because development aid isn't exactly a priority in US foreign policies (speaking of % of GNI, only Italy spends less. The other 20 developed countries donate up to 5 times more). I'd bring human rights and American values in the foreground again. An example for good foreign policy was the reaction against Uzbekistan after the Andischan massacre or the support for the Ukrainian opposition. Improvable are some of the trade relationships, the steel protectionism for example was a policy which cost the US ressources for the benefit of only few persons, or Guantanamo, which should immediately be closed - it's labeled a domestic issue by the US government but it has a big impact on the image of the US nonetheless.