While the disastrous and illegal bombing of Cambodia and sabotaging Vietnamese peace talks just to win the '68 election don't qualify. in my book as efforts designed to end the war

Comments like this are exactly why Nixon's run is a great Shakespearian story. It's got dramatic irony up the arse.

"The disastrous and illegal bombing of Cambodia" - that was deemed necessary because North Vietnamese troops were using Cambodia to ferry in troops and materiel for use in Vietnam.

Why were they using Cambodia? Because Congress had made it illegal (against the advice of people on the ground in Vietnam) for US forces to operate in Cambodia.

Why did they ban US forces from operating in Cambodia? Because thanks to the increasing casualty rate of US troops, public opinion was against an escalation of the war and were in denial that the war was already being fought in all parts of Indochina (the equivalent of Roosevelt being forced to fight WWII in Italy - and only Italy).

Why were more US servicemen dying? Because instead of allowing US forces to fight the North Vietnamese forces coming in from regions without Vietnam, congress and the public demanded that troops be brought home and their resources cut - further imperilling the troops (not to mention... uh, Vietnamese people) left in Vietnam, and leaving the only resource available to protect non-communist controlled Vietnamese territory (and the US troops stationed there) bombers and aircraft.

And why did the various air campaigns in Cambodia turn out to be ineffective? The US was banned from going into Cambodia to identify targets, acquire human intelligence and generally verify that everything was being done right. The people who were doing those jobs - the Cambodians - told the US out of desperation that everything was cool and they should continue bombing.

What method did Nixon actually want to use to end the war? More troops, more diplomacy, less bombing. What method was he forced into by his own public (and also a cynical North Vietnam regime using US public opinion to get what they wanted)? Fewer troops, less diplomacy, more bombing.

and sabotaging Vietnamese peace talks just to win the '68

This is also good, in that Kissinger is evil for sabotaging the peace talks. Peace talks that North Vietnam had no intention of having UNTIL the elections were over and the US had a leader they viewed as having authority. Peace talks that Kissinger himself was sent by the Johnson administration to start in the first place two years before the election.