How should the U.S. deal with other countries?

There are two main ways of thinking about how we should “deal with” other countries.  We can say that one of these ways of thinking is more selfish while the other is more idealistic.
The first way of thinking holds that we should deal with other countries based on what is good for the United States.  We should be nice to them if it will help us and we should be tough with them if it will help us.  If foreign countries abuse their people, we should only care if it affects us.  Therefore, for example, we should not try to make the Turkish government be less oppressive.  We should support them as long as they help us fight terrorism and/or as long as they are on our side against Russia.  Their support in these areas is much more important to us than whether they put journalists in jail for opposing their president.  This kind of thinking can be called “realism” because it says that, in the real world, we have to look out for our own interests before anyone else’s.
A second way of thinking is more idealistic.  It says that we should care mostly about doing good in the world and trying to get others to do good as well.  We should pursue our ideals, not our interests.  Therefore, even if we feel like we need the Philippines as an ally against China, we should not look the other way when their new president has the police and vigilantes kill thousands of suspected drug dealers.  We should push the Philippines to treat their people properly, even if it makes them less inclined to like us.  In this view, we should go around trying to help other countries become more democratic, even if it costs us money and lives.  For example, this view might argue that we were right to invade Iraq and to stay there trying to make them into a democracy.  This is true because democracy is a good thing and it would be good for the Iraqi people if they had a democracy.
So, which of these views fits more with your own?  Should we be selfish/realistic and look out for our own interests first?  Should we base our actions on our values and try to make the world a better place even if it costs us in the short term?  This is a question that each American must try to decide for him or her self.