Okay kiddo, so you know how sometimes people don't always agree with each other? Well, that's kind of what's happening with the United States' foreign policy. The U.S. is a big country with lots of important people making decisions on how we interact with other countries around the world. But sometimes, some people don't like the way those decisions are made or the actions the U.S. takes.
For example, let's say the U.S. decides to go to war with another country. Some people might think that's a bad decision and criticize the U.S. for starting the war. They might say that war is never the answer and that there could have been a better way to solve the problem.
Others might criticize the U.S. for not doing enough to help other countries or for only helping them for selfish reasons. They might argue that the U.S. should be doing more to help with issues like poverty or human rights abuses.
Critics of U.S. foreign policy might also point out that other countries might not like the U.S. very much because of some of the decisions it has made in the past. They might argue that the U.S. should do more to improve its relationships with other countries and work towards a more peaceful world.
Basically, criticizing U.S. foreign policy means saying that you don't agree with some of the decisions the U.S. has made or the way it interacts with other countries. It's like saying "I don't like what you're doing and I think you could do better."