Losing Vietnam (41 page)

The enemy struck early on 1 January 1975, with simultaneous attacks against the Phnom Penh perimeter. A document the 3rd FANK Division seized from a killed battalion commander in the 2nd KC Division on 4 January provided the strategic plan for the enemy's dry-weather campaign.
²⁰⁷
The three prime objectives were the ammunition depot at Kantauk, the Pochentong Airfield, and the Mekong River. The troops involved in the offensive would be eleven divisions with more than a hundred battalions consisting of approximately thirty-three thousand soldiers. The offensive was divided into six sections. First, in the west section, the 1st and 3rd KC Division were to capture Pochentong in three days. Second, in the northwest the equivalent of two divisions were to sever Route 5 and neutralize the 7th FANK Division. Third, south of Route 4, the 2nd KC Division was to make a dash for the munitions depot at Kantouk. Fourth, between the Tonle Sap and the
Mekong, one division was to destroy the naval base at Chrui Chang War. Fifth, four divisions were to interdict the Mekong. And finally, in the south there were territorial or regional forces with no specific objective.

The document specified that the military operations were to be conducted simultaneously and that troops were not to dig trenches but were to launch the assault and that the capture of Pochentong Airfield would deny all governmental individuals an escape. The initial attacks played out as written. As in 1974, the main attack was from the northwest sector toward Pochentong Airfield. But this time FANK was ready. Consequently, the enemy suffered greatly. Attacks elsewhere on the perimeter—particularly from Phnom Baset in the north, from the northeast, and from the eastern banks of the Mekong—pinned down the intervention units. The communists drove a major salient in the northwest, but friendly units flown from the provincial enclaves stabilized the situation. North of Phnom Penh, excellent air support helped the 7th Division halt the enemy's advance. By 8 January, FANK had stopped cold the initial attack on the Phnom Penh perimeter and the crisis had passed. The enemy had taken very heavy casualties. This was a major victory at the Phnom Penh perimeter; nevertheless, Pochentong Airfield was constantly under sporadic 107 mm rocket fire.

On 17 December 1974, the joint staff J-2 provided its best estimates of the communist force strengths—sixty-eight thousand regulars and fifteen thousand popular forces. The popular forces and village militia were necessary for population control. The main force combatants had approximately fifty-three thousand troops available for major attacks. The popular force strength had been much higher a year previously, but it had been greatly reduced by combat losses and by many popular force battalions' being upgraded to main force combatants. Therefore, when the communist high command committed eleven divisions, encompassing thirty-three thousand combatants, to attack Phnom Penh and the Mekong in the 1975 dry-weather campaign, it was committing almost two-thirds of its available main force units, surpassing the twenty-six thousand friendly troops in the seventy-eight intervention battalions defending the capital region in late December 1974. However, FANK rapidly increased its defensive units as both sides escalated the combat in the capital region.

The communists very quickly broke off outlying units and reinforced troops at Phnom Penh and the Mekong.
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Between December 1974 and January 1975, they withdrew fourteen battalions each from MR-6 and -9 and twenty-six battalions from MR-2 and they formed ten new battalions, thereby greatly increasing the force surrounding Phnom Penh from sixty to ninety-five battalions and the Lower Mekong from ten to forty battalions.

The enemy had overrun several marine positions of the lower Mekong. The communists had the preponderance of forces in the lower Mekong, which, because of the situation around Phnom Penh, the government had neglected. The situation was serious and required urgent attention.

The enemy pressure in the lower Mekong continued unabated and after 9 January was much more intense than around Phnom Penh. The communists planned and executed well their strategy to close the lower Mekong. Responding to this threat, FANK reinforced its troops occupying the terrain controlling three choke points on the lower Mekong River. On 4 February, utilizing water mines against shipping, the enemy forced Mekong convoy TP-114 to turn back. North of Banam, the key areas of Prek Yuon and Dei Doh subsequently fell, and the friendly positions at the lower choke points were overrun in late February. The enemy defeated two battalions on the key Peam Reang Island, with a loss of more than four hundred men. Without friendly control of the riverbanks at the narrows, the Mekong was closed—at least until the next flood stage, thereby forcing the United States to turn to a massive airlift to resupply Phnom Penh and the besieged enclaves.

At the end of February, a malaise had permeated Cambodia. A growing number of desertions were negating the government's increased efforts to implement the draft. MEDTC estimated that more than fifty-three hundred had deserted during January and February; without any effective control, the streets of Phnom Penh were full of deserters. Many of the intervention units had been severely bloodied, and there was a distinct lack of not just the offensive spirit but all combativeness. Many units were willing to abandon positions rather than stand and fight; the future performance of many units was at this time definitely unpredictable. Yet, by the end of February the enemy had not renewed its attacks on the Phnom Penh perimeter, most probably
because of the heavy losses it had absorbed in the New Year's offensive. Approximately half of the enemy troops attacking Phnom Penh had been killed or injured.

This was undoubtedly a crucial period for Cambodia. In early March, to get a sense of the future, the USSAG intelligence staff prepared a special study comparing the situation at the end of February 1974 with that at the end of February 1975.
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According to the study, in their 6 January 1974 initial attack the Khmer communists made a major penetration in the northwest sector and successfully crossed the Prek Thnot River in the southern sector, enabling them to fire 105 mm rounds into Phnom Penh. However, by the end of February, because of their piecemeal attacks and the lack of command and control, FANK had pushed the enemy back to the Phnom Penh defense perimeter except for gains in the northeastern sector.

In 1975, the communists had improved their command and control, which resulted in more coordinated attacks, and they had increased their total strength from 166 to 230 battalions. They had committed ninety-two to a hundred battalions against the capital and approximately forty battalions to the lower Mekong interdiction campaign. These forces notwithstanding, their initial attack on 1 January had been stopped cold, resulting in major casualties. Renewed attacks at the end of February resulted in inroads into the Phnom Penh defensive perimeter in the northwestern sector, letting the enemy conduct heavy attacks by fire against Pochentong Airfield. As in 1974, it also had some northeastern sector gains. The military situation around Phnom Penh was quite similar to what it had been in 1974; the major difference was that the communists had managed to successfully interdict the Mekong River.

In the beginning of January 1975 there was appreciably more ammo, rice, and petroleum stored in Phnom Penh than there had been during 1974's nearly critical shortages. The improved supply circumstances, and the enemy having not fired 105 mm artillery rounds into the city, enabled the internal situation to remain calm. Obviously, the 107 mm rocket interdiction had much less effect on the Phnom Penh citizenry: in 1975 the city received 231 rounds, as compared to only 10 in 1974. However, the KC increasingly interdicted Pochentong, trying to curtail the airland resupply. FANK's high ammo consumption rate
in 1975, although it was much lower than it had been in 1974, continued to draw down stocks so that the ammo supplies for both ground and air at the end of February 1975 were lower than they had been in the same month in 1974.

While FANK was conserving ammo, the communists were expending theirs at a much faster rate than they had in 1974. As mentioned, a captured document indicated that the enemy would attack Pochentong and Phnom Penh with a great increase in its command structure from January 1974, when it had only two divisions. And it had markedly improved its organizational structure (see
table 17
). Equally important was that the enemy had strengthened its logistical system; its troops had many more heavy weapons. The communists had doubled their firepower and had more ammo reserves. Both were relatively small, however, when compared to FANK's.

While the enemy now utilized more forces, was better equipped, and had more firepower, FANK was encumbered by the strict ammunition conservation requirement. The average daily expenditures had been reduced from 627 short tons in January–February 1974 to 432 short tons in the same months of 1975. How much of this reduction resulted from ammo restrictions and how much from the combat situation, which cooled off somewhat around Phnom Penh after mid-January, could not be determined. I believe it was mostly the result of the situation. The expenditures at 432 short tons were 50 percent greater than the 290 short-ton conservation-authorized supply rate, which came as no surprise.

The tremendous disparity in firepower between the FANK and the communists is brought home when one recognizes that the enemy expended several thousand short tons per month of ammo and the friendly troops expended 432 short tons per day.
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So, notwithstanding enemy improvements in command and control, weapons density, and logistics resupply, the Cambodians still had a major advantage in firepower and tactical and strategic mobility. However, they lagged in several intangibles, particularly leadership. A quick review of army, navy, and air force performance provides insights into the balance of power.

A comparison between 1975 dry-season FANK command and control techniques and those of 1974 indicates some notable improvements.
For example, FANK had been much more effective during 1975 in its use of supporting artillery and air and its armored mobility in conjunction with infantry units. There were many examples of leadership initiatives at battalion and, albeit less frequently, brigade and division levels. All of these positively contributed to the fact that friendly forces had extracted a significantly higher casualty toll from the enemy than in the previous year.

However, the tactical and strategic weaknesses evident in 1974 persisted. More disappointing than FANK's failure to improve unit strengths was its lack of success in overcoming leadership and command deficiencies. Despite urgings to the contrary, the army had failed to take the initiative and continued to suffer from centralized decision-making and poor execution of plans. The indecisive and piecemeal commitment of forces in 1975 evidenced this when, for example, the general staff urgently needed to reinforce units on the lower Mekong but failed to do so.

The attrition of both sides was much greater in 1975 than it had been in 1974.
²¹¹
FANK's tactical mobility, its much improved effectiveness of the air force, its better-prepared defensive positions, and its having been forewarned of the communist attack all contributed to significant enemy losses in 1975. However, the enemy's larger, better-equipped and -coordinated force, with more weapons and ammunition, also took a toll on FANK (see
table 23
).

On the bright side, over the previous twelve months, under Brig. Gen. Ea Chhong the Khmer Air Force had made significant improvements. Aircrew totals had increased from ninety to 141. Sortie rates also significantly increased. For example, T-28D operational sorties increased from 2,790 in January–February 1974 to 3,848 in January–
February 1975.
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Other improvements that lent themselves to statistics included bomb damage assessments and visual reconnaissance. Maintenance improvements were also significant.
²¹³
The Khmer Air Force was currently conducting airlift and strike aircraft phase inspections, and a decline in aircraft losses attributed to maintenance was evident. The supply system to keep aircraft operation-ready also showed improvement. The Khmer Air Force improvements were one of the most noteworthy accomplishments of the Cambodian military.

Table 23.
Countrywide Casualty Figures and Attrition

Source
: DAMSREP/DAO, Phnom Penh, Cambodia.

The navy's performance was continuously rated as high during January and February 1974. Concrete examples included the successful transit of Mekong convoys with moderate damage, few casualties, and relatively little loss of cargo; the successful regular resupply of Kompong Cham and Kompong Chhnang; and the support given army operations in the Bassac and Phnom Penh areas. During January–February 1975, navy personnel performed adequately. However, the introduction of mine warfare (with the resultant equipment losses), the increased tempo of operations, and decreased maintenance of the riverine craft contributed to a greatly depleted naval force. In January, the introduction of mining tactics on the Mekong and the presence of enemy forces all along the lower Mekong sealed off this avenue of resupply to Phnom Penh. The mining tactics would not have enjoyed as much success had the marine units been able to hold their defensive positions. Cambodia lost all of its marine positions on the lower Mekong south of Koch Reah and abandoned several other positions.