The so-called Kissinger Cables, made available by anti-secrecy website Wikileaks this week, reveal a US State Department stuck between a hostile Congress, a deteriorating situation on the ground and a pleading Khmer Republic during the final months of US bombings in Cambodia in 1973.

The last months of the campaign saw an escalation of bombings designed to halt the Khmer Rouge push towards Phnom Penh as heavy fighting erupted around the capital.

A cable from the State Department on April 2, 1973, quotes a press report stating: “The Khmer Rouge Sunday redoubled offensive operations throughout the country despite 25 consecutive days of saturation bombing raids by American B52 bombers and F111 fighter jets.”

Cables in the same week from Phnom Penh describe a “critical situation” along the Mekong, and a possible supply crisis.

With the US deploying “maximum air support”, difficulties are blamed on Khmer National Armed Forces (FANK) morale.

“The difficulty is not so much enemy strength, but FANK’s willingness to fight on,” a secret cable on April 2 reads.

The situation clearly worsened by April 21, when then-US Ambassador Emory Swank proposed the evacuation of some embassy personnel as Khmer Rouge forces drew closer to Phnom Penh, warning that the “employment of US air power in the populated urban perimeters presents more serious problems”.

Cables also highlight a growing unease on the part of US officials toward reports of civilian casualties and refugees fleeing bombed areas.

“We continue to hear reports of civilians killed by B-52 air strikes. All of these reports are second-hand, however and we have been unable to locate anybody who actually has witnessed civilian casualties,” an April 13 cable reports.

Officials were also quick to place the onus on enemy forces.

“By forcing these people to live with and support their troops, the enemy has deliberately exposed them to air attacks against legitimate military targets,” the cable reads.

The cables also show US recognition that the Khmer Rouge were exploiting air strikes to win over peasants.

“Another quite different explanation is that the enemy has consciously been trying to spread rumours of large numbers of civilians killed,” the same cable reported.

Despite increasing casualties and US Congress setting an August 15 deadline for the cessation of bombing, Lon Nol continued to press Nixon for air raids, the cables show, as hopes for a negotiated end to the conflict dwindled.

US hopes of containing reports of civilian casualties were dashed when B-52 bombers accidently dropped their payload on Neak Luong on August 6, killing over a hundred civilians.

A letter of condolence to the victims sent to Lon Nol sent on August 7 said the US “bow[s] before their sacrifices and their suffering . . . that the Khmer people so courageously bears in defensing its’ independence.”

Two days before the August 15 deadline, a more optimistic picture is presented. “The GKR appears to be making a concerted effort to . . . screw up its own courage to confront whatever challenge must be faced after August 15,” a cable reports.

In a radio address on August 11, Lon Nol told the nation that despite rumours, Phnom Penh would not fall.

“We have no reason to worry,” he said.