The Vietnam War was a conflict involving the United States, between communist North Vietnam and the US-allied South Vietnam.
History
U.S. troops were sent to fight communism but they complained they were not being really supported by Washington, D.C. remaining undermanned and underfunded. They didn't view it as a real war, as until 1964 neither side engaged in a direct approach. Each side fought for a different reason, with the natives were fighting for their homes. Robert McNamara asked The Comedian to go there as a military advisor and a figurehead to inspire the troops. The Comedian joined Charlie Company and played a major role, ordering the first direct engagement against the Viet Cong.
In August, VC gunboats attacked U.S. destroyers such as USS Maddox in international waters. The troops believed that it was the chance they needed to escalate the war, but President Lyndon B. Johnson had no response. Dismayed, the Comedian led a mock attack against their own destroyers two days later, forcing the President to request the Congress to pass a resolution to take all necessary measures, and U.S. airplanes attacked gunboats and facilities in North Vietnam in reply. The war escalated.
The Comedian would continue to serve for an undetermined amount of time working for the government in Vietnam.
The war has been won by the US, largely due to the deployment of Doctor Manhattan, who was used as a weapon since March 1971; the conflict was ended in only two months. Many of the communist forces express their desire to surrender to Manhattan personally, seeing him as some sort of deity. When Manhattan meets Blake there, he reflects on how "deliberately amoral" the man is, and that the conflict suits him.
It is in Vietnam's capital city, Saigon, in the closing days of the war, that the Comedian kills a young Vietnamese woman whom he had impregnated during a physical relationship. The woman is hurt and offended by Blake's desire to leave the country and her behind with no father for their child. She breaks a bottle and slashes his face; in his extreme anger, Blake shoots her while Manhattan, a witness, does nothing to prevent him.
Vietnam is later mentioned as becoming the 51st US state.