Uh, sorry, but no. That party had allowed the conditions that led to the invasion - unopposed sanctuary for people who were killing our troops and using that border for protection. Nixon did nothing but respond to a condition that only allowed that party to maintain office through connivance with the North Vietnamese. Twisting that to blame him for the Khmer Rouge was very popular back when it was chic to blacken his reputation by any means necessary (e.g. The Killing Fields) but is a historical injustice of the first order.
"Uh, sorry, but no. That party had allowed the conditions that led to the invasion - unopposed sanctuary for people who were killing our troops and using that border for protection. Nixon did nothing but respond to a condition that only allowed that party to maintain office through connivance with the North Vietnamese. Twisting that to blame him for the Khmer Rouge was very popular back when it was chic to blacken his reputation by any means necessary (e.g. The Killing Fields) but is a historical injustice of the first order."
You are mistaken. The invasion of Cambodia was an attempt by Nixon to move the war in Vietnam to a place in which the U.S. would have some success.
This was based on mistaken intellgence that the NLF and North Vietnamese had their headquarters in Cambodia, which was erroneous.
The Khmer Rouge was a small, extremist minority organization before Nixon invaded Cambodia. The ensuing violence and chaos which followed the U.S. invasion of Cambodia only allowed the Khmer Rouge to step into the power vacuum which followed.