Regarded as a premier tactician, Johnson became skeptical that the level of resources given to the Vietnam War, much of which went into 'find, fix, and destroy the big main force units' operations, could deliver victory.

Returning to the United States, Johnson was assigned to the Office of the Chief of the Army Field Forces, Fort Monroe, Virginia.

On 3 July 1964, Johnson was appointed the 24th Chief of Staff of the United States Army; his reputation as an expert tactician led to him being selected over candidates with more seniority.

[2] However, Johnson publicly said there was no alternative to disrupting enemy main force units in the Central Highlands as preventing them from establishing base areas in the middle of the country was essential.

Johnson started the process to have Westmoreland replaced in Vietnam, and commissioned the PROVN Study, which noted that "aerial attacks and artillery fire, applied indiscriminately, also have exacted a toll on village allegiance."

There was a deep-seated reluctance among the Joint Chiefs of Staff to interfere with the command decisions of Westmoreland, but harassing artillery fire, by United States forces at least, was greatly reduced.

Commander in Vietnam, General William Westmoreland, had little choice but to engage the enemy's main formations, which had to be prevented from securing base areas where they could concentrate.

Johnson was instrumental in altering the focus to a counterinsurgency approach, but was frustrated at the US Congress' refusal to provide the manpower necessary for successful pacification.

In his later years Johnson said it had been obvious that US national mobilization was required to win in Vietnam, and he regretted not resigning in protest at the government asking the army to fight a war without hope of ultimate victory.

As Chief of Staff, one of Johnson's noteworthy accomplishments was creating the office of the Sergeant Major of the Army to improve the quality of life for enlisted personnel.

For three years, General Johnson headed the Freedoms Foundation at Valley Forge and afterwards worked as a banking executive until retiring for good.

When his battalion had been forced to withdraw from their hill position by a series of fierce attacks by an overwhelming number of the enemy, Colonel Johnson immediately directed a counterattack in an attempt to regain the vitally important dominating terrain.

When his mortars became inoperable and his casualties very heavy due to the tremendous firepower and numerically superior enemy forces, he realized the necessity for withdrawal.

His conspicuous devotion to duty and selfless conduct under enemy fire provided an inspiring example to his men and prevented a serious penetration of friendly lines.