Lyndon Johnson, Speech at Johns Hopkins University, "Why are we in South Vietnam"

Why are we in South Vietnam? We are there because we have a promise to keep. Since 1954 every American President has offered to support the people of South Vietnam. We have helped to build and we have helped to defend. Thus, over many years, we have made a national pledge to help South Vietnam defend its independence. I intend to keep our promise. To dishonor that pledge, to abandon this small and brave nation to its enemy and to the terror that must follow would be an unforgivable wrong. We are there to strengthen world order. Around the globe from Berlin to Thailand are people whose well-being rests, in part, on the belief they can count on us if they are attacked. To leave Vietnam to its fate would shake the confidence of all these people in the value of American commitment. The result would be increased unrest and instability, or even war.