1 December
President Johnson and his top-ranking advisers met to discuss plans to bomb North Vietnam.
After some debate, they agreed on a two-phase bombing plan with an objective of ending North Vietnamese support of VC operations in South Vietnam and maintaining the security of other non-Communist nations in Southeast Asia.

2 December
Two USAF C-47s were modified at Bien Hoa Air Base to mount three GAU-2/A Miniguns.
By 15 December both aircraft had been converted into FC-47 gunships and were assigned to the 1st Air Commando Squadron for combat testing.

7-9 December
The Battle of An Lao began when the PAVN/VC captured the district headquarters of An Lao, Bình Định, about 300 miles (480 km) from Saigon.
The PAVN/VC were successful in repeatedly beating back large numbers of counterattacking ARVN troops.
This battle was the first time in that area that the PAVN/VC "used the new tactic of coordinating main force units with local and guerrilla forces."
The battle resulted in 150 PAVN/VC killed, 300 ARVN casualties and two U.S. killed.

9 December
A VC force attacked and overran an ARVN outpost 4.5 miles (7.2 km) from Tam Kỳ.
The ARVN, supported by U.S. Marine and Army helicopters, killed 70 VC and captured 39 weapons for the loss of eight ARVN and one U.S. advisor killed.

14 December
Operation Barrel Roll began, a covert interdiction and close air support campaign by the U.S. Air Force 2nd Air Division (later the Seventh Air Force) and U.S. Navy Task Force 77, conducted in the Kingdom of Laos.
The campaign would continue until 1973.

16 December
The U.S. Embassy in Saigon reported that Prime Minister Huong had successfully repressed Buddhist demonstrations against the government, had imposed censorship and shut down ten newspapers suspected of collaborating with communists.

19 December
A Cambodian diplomat in Hanoi reported that "Anti-aircraft guns have been positioned on rooftops, and people are busy digging trenches in the streets."
 Author Pierre Asselin later said, "Although Americans did not know it at the time, the Vietnam War had begun."

20 December
Junta leader General Khánh led a group of military officers called the "Young Turks" in a coup.
They dissolved the civilian High National Council, arrested a number of military officers and civilian officials, and created an Armed Forces Council.
Hương remained as Prime Minister.
Ambassador Taylor was outraged by the coup, berating Khánh and the Young Turks who, he said, had acted "without consulting with U.S. representatives and in disregarding our advice on important matters."

22 December
In an address over military radio, Khánh said, "We make sacrifices for the country's independence and the Vietnamese people's liberty, but not to carry out the policy of any foreign country."
He said it was "better to live poor but proud as free citizens of an independent country rather than in ease and shame as slaves of the foreigners and Communists."
Khánh pledged support for both Hương and Suu's civilian rule, and condemned colonialism in a thinly veiled reference to the US.

23 December
In an exclusive interview with Beverly Deepe published in the New York Herald Tribune on December 23, Khánh said "if Taylor did not act more intelligently, Southeast Asia would be lost" and added that Taylor's "attitude during the last 48 hours—as far as my small head is concerned—has been beyond imagination".
Justifying the removal of the HNC, Khánh said they were "exploited by counter-revolutionary elements who placed partisan considerations above the homeland's sacred interest."

In the evening, Khánh convinced his fellow officers to join him in lobbying Hương to declare Taylor persona non grata and expel him from South Vietnam.
However, someone in the junta was a CIA informant and reported the incident, allowing American officials to individually lobby the officers to change their stance.
At the same time, the Americans informed Hương if Taylor was expelled, US funding would stop.
The next day, the generals changed their mind and when they met Hương at his office, only asked him to formally denounce
1 December
President Johnson and his top-ranking advisers met to discuss plans to bomb North Vietnam. After some debate, they agreed on a two-phase bombing plan with an objective of ending North Vietnamese support of VC operations in South Vietnam and maintaining the security of other non-Communist nations in Southeast Asia.
2 December
Two USAF C-47s were modified at Bien Hoa Air Base to mount three GAU-2/A Miniguns. By 15 December both aircraft had been converted into FC-47 gunships and were assigned to the 1st Air Commando Squadron for combat testing.
7-9 December
The Battle of An Lao began when the PAVN/VC captured the district headquarters of An Lao, Bình Định, about 300 miles (480 km) from Saigon. The PAVN/VC were successful in repeatedly beating back large numbers of counterattacking ARVN troops. This battle was the first time in that area that the PAVN/VC "used the new tactic of coordinating main force units with local and guerrilla forces." The battle resulted in 150 PAVN/VC killed, 300 ARVN casualties and two U.S. killed.
9 December
A VC force attacked and overran an ARVN outpost 4.5 miles (7.2 km) from Tam Kỳ. The ARVN, supported by U.S. Marine and Army helicopters, killed 70 VC and captured 39 weapons for the loss of eight ARVN and one U.S. advisor killed.
14 December
Operation Barrel Roll began, a covert interdiction and close air support campaign by the U.S. Air Force 2nd Air Division (later the Seventh Air Force) and U.S. Navy Task Force 77, conducted in the Kingdom of Laos. The campaign would continue until 1973.
16 December
The U.S. Embassy in Saigon reported that Prime Minister Huong had successfully repressed Buddhist demonstrations against the government, had imposed censorship and shut down ten newspapers suspected of collaborating with communists.
19 December
A Cambodian diplomat in Hanoi reported that "Anti-aircraft guns have been positioned on rooftops, and people are busy digging trenches in the streets."  Author Pierre Asselin later said, "Although Americans did not know it at the time, the Vietnam War had begun."
20 December
Junta leader General Khánh led a group of military officers called the "Young Turks" in a coup. They dissolved the civilian High National Council, arrested a number of military officers and civilian officials, and created an Armed Forces Council. Hương remained as Prime Minister. Ambassador Taylor was outraged by the coup, berating Khánh and the Young Turks who, he said, had acted "without consulting with U.S. representatives and in disregarding our advice on important matters."
22 December
In an address over military radio, Khánh said, "We make sacrifices for the country's independence and the Vietnamese people's liberty, but not to carry out the policy of any foreign country." He said it was "better to live poor but proud as free citizens of an independent country rather than in ease and shame as slaves of the foreigners and Communists." Khánh pledged support for both Hương and Suu's civilian rule, and condemned colonialism in a thinly veiled reference to the US.
23 December
In an exclusive interview with Beverly Deepe published in the New York Herald Tribune on December 23, Khánh said "if Taylor did not act more intelligently, Southeast Asia would be lost" and added that Taylor's "attitude during the last 48 hours—as far as my small head is concerned—has been beyond imagination". Justifying the removal of the HNC, Khánh said they were "exploited by counter-revolutionary elements who placed partisan considerations above the homeland's sacred interest."
In the evening, Khánh convinced his fellow officers to join him in lobbying Hương to declare Taylor persona non grata and expel him from South Vietnam. However, someone in the junta was a CIA informant and reported the incident, allowing American officials to individually lobby the officers to change their stance. At the same time, the Americans informed Hương if Taylor was expelled, US funding would stop. The next day, the generals changed their mind and when they met Hương at his office, only asked him to formally denounce
1964 in the Vietnam War