Is the American era of hegemony over?

After studying the notes, and watching the video, respond to the following:
It seems as if America has been seeking ‘monsters to destroy’ for a long time.
What are some of the reasons we have used to justify our adventures abroad?
How would you characterize this ‘hunt’, based on the week’s materials? Have we gotten it ‘about right’? Have we overextended?
Is the American era of hegemony over?