Uniquely, it had gone through three expansion phases based on feudalism, merchant capitalism, and industrial capitalism, respectively. Each expansion phase had kindled a conflict phase without, however, leading to a universal empire incorporating all or most of the civilization. When Quigley wrote, it was not clear whether the United States could or would bring the dubious blessings of universal empire to Western Civilization. In recent decades, the will to extend US imperialism everywhere has certainly been in evidence. The elite wields this rhetoric against its own backward American people, who are expected to pay for the elite's moral and political lost weekends, whatever the damage to the original republican scheme which the people were blind enough to let go.
Empires tend to proclaim some universal mission as justification for their existence.
This may be the first time that an empire has proclaimed the suicide of its civilization as part of its mission. The best choice of all would be to abandon the path of empire, for empire destroys not just hapless foreigners in its path but the core civilization from which it arose. Of course ruling elites do not give up their projects willingly. Some pressure from below will be needed. Now there is a task worthy of a new millennium.