Newly declassified US government documents show former president Richard Nixon lied about the secret war in Cambodia even after US involvement became known.
The documents from the Nixon years shed light on the Vietnam War, the struggle with the Soviet Union for global influence and a president who tried not to let public and congressional opinion get in his way.
On May 31st, 1970, a month after Mr Nixon went on TV to defend the previously secret US bombings and troop movements in Cambodia, asserting that he would not let his nation become "a pitiful, helpless giant", the president met his top military and national security aides at his Western White House in California.
Revelation of the operation had sparked protests and congressional action against what many politicians from both parties considered an illegal war.
Mr Nixon noted that Americans believed the Cambodian operation was "all but over", even as 14,000 troops were engaged across the border in a hunt for North Vietnamese operating there.
In a memo from the meeting marked "Eyes Only, Top Secret Sensitive", Mr Nixon told his military men to continue doing what was necessary in Cambodia, but to say for public consumption that the US was merely providing support to South Vietnamese forces when necessary to protect US troops.
"That is what we will say publicly," he asserted. "But now, let's talk about what we will actually do." He instructed: "I want you to put the air in there and not spare the horses. Do not withdraw for domestic reasons but only for military reasons. We have taken all the heat on this one.
"Publicly, we say one thing. Actually, we do another," he told aides.
The release of some 50,000 pages of documents by the National Archives means about half the national security files from the Nixon era are now public.
AP