2 May
VC commandos eluded detection and placed an explosive on the USNS Card.
The ship, moored in the Saigon River, sunk and 5 American sailors were killed.
The USNS Card was later raised and repaired.

About 1,000 students participated in the first major student demonstration against the Vietnam War, marching in New York City as part of the "May 2nd Movement" that had been organized by students at Yale University.
Marches also occurred in San Francisco, Boston, Seattle, and Madison, Wisconsin.

9 May
Former President Diem's brother, Ngo Dinh Can was executed by order of General Khanh.
U.S. Ambassador Lodge asked that Can's life be spared, but Khanh chose to placate the militant Buddhist movement in South Vietnam.
Earlier in the day, Phan Quang Dong, the former chief of Can's secret police force, was executed at the municipal stadium in Huế before a crowd of 40,000 people.

A plot to assassinate Secretary of Defense McNamara was foiled, three days before his visit to South Vietnam, with the arrest of VC agent Nguyễn Văn Trỗi.
Trỗi had planned to detonate a bomb as McNamara was being driven across the Cong Ly Bridge in Saigon on 12 May.
12 May
American Ambassador Lodge said in a secret meeting that Buddhist leader Thich Tri Quang is "ambitious, anti-Christian, full of hatreds, and agitating against [the government of] Khanh.
He said that "some communist infiltration of Buddhists exists."

16 May
Twelve men in New York City publicly burned their draft cards to protest against the war.
The demonstration, with about 50 people in Union Square, was organized by the War Resisters League.

19 May
The U.S. began "Operation Yankee Team", low-level and medium-level reconnaissance flights from South Vietnam over PAVN/VC strongholds in neighboring Laos, at the request of the Royal Laotian Armed Forces.
Two days after flights began over southern Laos in the area that was part of the Ho Chi Minh Trail, U.S. Navy planes would conduct sorties over northern Laos.

21 May
Pathet Lao antiaircraft artillery damaged a U.S. Navy RF-8A Crusader that was flying a photographic reconnaissance mission.
The RF-8A, flown by U.S. Navy Lieutenant Charles Klusmann, burned for 20 minutes in the air but Klusmann was able to return for a safe landing aboard the USS Kitty Hawk.

23 May
Western sources estimated the PAVN to number 16 divisions totaling 280,000 men, plus militias with 180,000 men, and a border force of 20,000 men.
A reserve militia force numbered 400,000.
North Vietnam had not yet infiltrated any elements of the PAVN into South Vietnam.

24 May
Senator Barry Goldwater, who would become the Republican Party candidate for President of the United States later in 1964, discussed the use of nuclear bombs against North Vietnam to interrupt supply lines for the VC in South Vietnam.
In the face of widespread criticism of his remarks, Goldwater said he was only "repeating a suggestion made by competent military people."
Democrats used Goldwater's statements about the use of nuclear weapons to portray him as an extremist in the election campaign.

27 May
President Johnson revealed the depth of his uncertainty about South Vietnam in a conversation with Senator Richard Russell.
Johnson said his advisers were telling him to "show some power and some force", but he didn't believe the American people were behind the war.
Russell agreed and expressed doubt that bombing North Vietnam would win the war.
Johnson said he didn't know how to get out of the Vietnam War, adding that he would be impeached if he were to withdraw from the war. "
I don't know how in the hell you're gonna get out unless they [the Senate Republicans] tell you to get out."
After the talk with Russell, Johnson telephoned his adviser McGeorge Bundy and said, "I don't think it [South Vietnam] is worth fighting for and I don't think we can get out.
 It's just the biggest damn mess I ever saw."

28 May
Khánh presided over a trial of the generals he toppled and accused of neutralism, in light of US pressure on him to give his opponents a hearing.
Minh was accused of misusing a small amount of money, before
2 May
VC commandos eluded detection and placed an explosive on the USNS Card. The ship, moored in the Saigon River, sunk and 5 American sailors were killed. The USNS Card was later raised and repaired.
About 1,000 students participated in the first major student demonstration against the Vietnam War, marching in New York City as part of the "May 2nd Movement" that had been organized by students at Yale University. Marches also occurred in San Francisco, Boston, Seattle, and Madison, Wisconsin.
9 May
Former President Diem's brother, Ngo Dinh Can was executed by order of General Khanh. U.S. Ambassador Lodge asked that Can's life be spared, but Khanh chose to placate the militant Buddhist movement in South Vietnam. Earlier in the day, Phan Quang Dong, the former chief of Can's secret police force, was executed at the municipal stadium in Huế before a crowd of 40,000 people.
A plot to assassinate Secretary of Defense McNamara was foiled, three days before his visit to South Vietnam, with the arrest of VC agent Nguyễn Văn Trỗi. Trỗi had planned to detonate a bomb as McNamara was being driven across the Cong Ly Bridge in Saigon on 12 May.
12 May
American Ambassador Lodge said in a secret meeting that Buddhist leader Thich Tri Quang is "ambitious, anti-Christian, full of hatreds, and agitating against [the government of] Khanh. He said that "some communist infiltration of Buddhists exists."
16 May
Twelve men in New York City publicly burned their draft cards to protest against the war. The demonstration, with about 50 people in Union Square, was organized by the War Resisters League.
19 May
The U.S. began "Operation Yankee Team", low-level and medium-level reconnaissance flights from South Vietnam over PAVN/VC strongholds in neighboring Laos, at the request of the Royal Laotian Armed Forces. Two days after flights began over southern Laos in the area that was part of the Ho Chi Minh Trail, U.S. Navy planes would conduct sorties over northern Laos.
21 May
Pathet Lao antiaircraft artillery damaged a U.S. Navy RF-8A Crusader that was flying a photographic reconnaissance mission. The RF-8A, flown by U.S. Navy Lieutenant Charles Klusmann, burned for 20 minutes in the air but Klusmann was able to return for a safe landing aboard the USS Kitty Hawk.
23 May
Western sources estimated the PAVN to number 16 divisions totaling 280,000 men, plus militias with 180,000 men, and a border force of 20,000 men. A reserve militia force numbered 400,000. North Vietnam had not yet infiltrated any elements of the PAVN into South Vietnam.
24 May
Senator Barry Goldwater, who would become the Republican Party candidate for President of the United States later in 1964, discussed the use of nuclear bombs against North Vietnam to interrupt supply lines for the VC in South Vietnam. In the face of widespread criticism of his remarks, Goldwater said he was only "repeating a suggestion made by competent military people." Democrats used Goldwater's statements about the use of nuclear weapons to portray him as an extremist in the election campaign.
27 May
President Johnson revealed the depth of his uncertainty about South Vietnam in a conversation with Senator Richard Russell. Johnson said his advisers were telling him to "show some power and some force", but he didn't believe the American people were behind the war. Russell agreed and expressed doubt that bombing North Vietnam would win the war. Johnson said he didn't know how to get out of the Vietnam War, adding that he would be impeached if he were to withdraw from the war. "I don't know how in the hell you're gonna get out unless they [the Senate Republicans] tell you to get out." After the talk with Russell, Johnson telephoned his adviser McGeorge Bundy and said, "I don't think it [South Vietnam] is worth fighting for and I don't think we can get out.  It's just the biggest damn mess I ever saw."
28 May
Khánh presided over a trial of the generals he toppled and accused of neutralism, in light of US pressure on him to give his opponents a hearing. Minh was accused of misusing a small amount of money, before
1964 in the Vietnam War