From ‘The Grand Chessboard’ (1997) by Zbigniew Brzezinski,

Never before has a populist democracy attained international supremacy. But the pursuit of power is not a goal that commands popular passion, except in conditions of a sudden threat or challenge to the public’s sense of domestic well-being. The economic self-denial (that is, defense spending) and the human sacrifice (casualties even among professional soldiers) required in the effort are uncongenial to democratic instincts. Democracy is inimical to imperial mobilization.

Democractic vales are inherently contradictory to empire building…