In the 1960s other countries referred to America landing on the moon saying "The Eagle has landed" This gives us some information, first it identifies who the Eagle is. Secondly it identifies the time period, the late 1900s. I believe that this references Vietnam and Korea. We were at that time a world superpower, emerging victorious from WWII, Great Britain destroyed, and previously occupied countries recovering from Hitler. Thus we were basically the "king" at the time. "Look at the smoke can you hear me a-screaming" I think that references war. Your hero has returned might reference the fact that America was trying to "save" the country that was being invaded, thus "Your hero has returned again"