China
You could be right about the threat of China.
Unfortunately or fortunately as the case may be, I see the West and China being pushed from opposite directions to a place of commonality. China already reminds me more of a giant corporation than a political entity.
Terrorism is a religious war that threatens millions of lives but the war between the East and West is cultural and I believe at this point in time it will be a bloodless war faught to the appearance of a draw over the next century.
The place of commonality will hopefully be a decent place to live but it will not be Utopia.