Use the quote below to answer the following question.
England's naval bases have been in all parts of the world and her fleets have at once protected them, ..and therefore, the surest means of supporting abroad the sea power of a country...Britain's power was everywhere that her ships could reach. ---Alfred Thayer Mahan's "The Influence of Sea Power Upon History", 1890
What did Mahan believe the US needed to do in order to succeed as an imperial power?