What is the appropriate way to "break off" an argument without being offensive?

I’m one of those people who don’t like to get into arguments that have no right answer. This includes arguments about politics, religion, correct punishment of crimes, etc. I’ll argue about math all day long since it does have a correct answer, just not politics.

Since these subjects are very subjective (due to the “no right answer”), there is going to be a lot of room for debate. Whenever I bring up an opinion in these topics, it is possible for me to get into a debate. I want to be able to stop these debates before either party gets too emotional / angry about the argument, and because I simply don’t like arguing.

What I don’t want to do is to make the other side angry about me cutting off the argument. I don’t want to make it sound like I am no longer going to argue because the other person is too stubborn / stupid to agree with me.

What is the best way to do this if I am in an argument? If I don’t like arguments, then there must be some way for me to solve the problem beside just not participating in a discussion.