The Americans entered the Vietnam War with the sole intention to prevent the spread of communism or as they liked to call it, "the domino theory". Through their actions to prevent this so called spread the Americans became very unpopular and did quite the opposite as most citizens fell to communism just to spite the Americans. Such actions include; the secret bombing of Cambodia in operation "Menu" and invasions of both Cambodia and Laos. .
In 1969, newly elected President Richard M. Nixon, aiming to achieve "peace with honor" in Vietnam, began to put his "Vietnamization" policy into place, which basically involved removing the number of American military soldiers in the country and transferring combat roles to the South Vietnamese. Military planners had based previous withdrawal plans on reductions in enemy forces. Vietnamization rested on the assumption that the combatants would not reach any kind of political settlement, or understanding, and that the fighting in the South would continue without any voluntary reduction in enemy force levels. A ceasefire agreement of January 23 1973 marked an end to Vietnamization. The agreement specified the complete withdrawal of all American military forces from South Vietnam, including advisors, and the end of all U.S. military actions in support of Saigon. Vietnamization in theory made perfect sense. Teach the South Vietnamese military to fend for themselves however with only four short years to achieve the desired results of Vietnamization, the United States found that they had overestimated the ability of the ARVN to match up against the well trained and highly motivated Vietcong and NVA. .
At the same times as all this, President Nixon resumed the secret bombing of North Vietnam and launched B-52 bombing raids over Cambodia, intending to wipe out NLF and North Vietnamese base camps along the border. The intensive secret bombing, code-named Operation "Menu", lasted for four years and was intentionally kept secret from those of public.