This quote, after describing a military that clearly CAN put its pants on both legs at once, so to speak?
Empires are sometimes created by power vaccuums. The American Imperium was not created by a series of successful wars of conquest (i.e, we didn't knock off in turn Carthage, Macedon, the Seleucids, etc.). A Europe that chose comfort and cradle to grave social welfare states flatly did not want to be bothered with creating world class militaries. They were all to eager to devolve that grunt work onto the uncouth Americans. It never entered their heads that a substantive conflict would appear between them and America in which the US would decide to ignore their wishes. They thought they were getting a free ride.
Europeans can march in the streets but they do not want to pay the costs and make the sacrifices necessary to seriously challenge American power. They want to take on the US in an August-off, 35 hour work week kind of way. With pieces of paper and lectures. The American superpower has been created more by European fecklessness than anything else.