War is a contagion, whether it be declared or undeclared. It can engulf states and peoples remote from the original scene of hostilities. We are determined to keep out of war, yet we cannot insure ourselves against the disastrous effects of war and the dangers of involvement. We are adopting such measures as will minimize our risk of involvement, but we cannot have complete protection in a world of disorder in which confidence and security have broken down.

Quarantine Speech (October 5, 1937)