The third major determinant of which scenario prevails will be American power and how it is used. The US will remain the most powerful country in 2020, but, paradoxically, the strongest state since the days of Rome will be unable to protect its citizens acting alone.
决定哪一种局面占据主导地位的主要决定因素将是美国的实力以及如何使用这一实力。美国在2020年依旧是最强大的国家，但是，自相矛盾的是，罗马时代以来最为强大的国家将无法独自保护其公民。