What are some international career opportunities for a CPA?

No such thing. A CPA license is state specific. You have to take the exam in the state where you want to practice and you are only licensed for that particular state. There are residence requirements as well. For example, if you live in Texas you would take the exam in Texas and you would be licensed to practice in Texas. If you are in New York, you would take the exam in New York and be licensed to practice in New York. There is no such thing as a license for the whole U.S. or "international."