What was it that Eisenhower warned us about in 1961?

This conjunction of an immense military establishment and a large arms industry is new in the American experience. . . .Yet we must not fail to comprehend its grave implications. . . . In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military-industrial complex. The potential for the disastrous rise of misplaced power exists and will persist.