This chapter examines the origins and consequences of national security institutions in the United States during the Eisenhower, Kennedy, and Johnson administrations. It explains the political logic shaping continuity and change in institutional design. The limited threat of bureaucratic punishment during Eisenhower and Kennedy prompted both to maintain integrated institutions through most of their presidencies. In contrast, fears that bureaucratic leaks would derail passage of his transformative social and economic legislation led Lyndon Johnson to adopt fragmented institutions. These fragmented institutions came at a cost: They degraded the quality of information that the bureaucracy provided. As a result, Johnson based the most consequential foreign policy choice of his presidency – the escalation in Vietnam – on incomplete and biased information. The analysis suggests that the costliest American foreign policy miscalculation of the Cold War was in part a tragic consequence of how Johnson resolved the trade-off between good information and political security.