If firms who are unionized in the USA say they have to expand abroad to remain competitive and viable, but would prefer to have no union representation in the new country or countries, what should unions do?

As more companies go global, what do unions do? If firms who are unionized in the USA say they have to expand abroad to remain competitive and viable, but would prefer to have no union representation in the new country or countries, what should unions do? Feel free to search the internet for supporting information. Requirements: Course subject is human resource management * Your original post should be approximately 250 words.