I read somewhere that toward the end of his administration, as Watergate was increasing pressure on him, Nixon put out feelers to see whether military leaders would support him in a "self-coup." The article cited an individual who was present at a meeting where Nixon, in a roundabout way, seemed to be probing for potential allies who would support him. Obviously the "coup" never happened, but is there any evidence that Nixon (or other individuals in the administration) were considering extreme measures such as this to prevent his removal from power?
James Schlesinger took preparations to make sure, just in case, but I don't think Nixon ever seriously considered a military coup or some of the more far out options often brought up in hindsight, like starting WWIII with the Soviet Union. This is a fundamental misread of Nixon's state of mind at the time. He was depressed in his final days, not angry-as someone who himself probably suffered from it not so long ago, severe clinical depression brings out a morose lethargy in a man. It's a very dead feeling, so different from being sad, so much worse-but that being said, it's not conducive to thinking along the lines it would take to consider such an option. Haig, Snowcroft and Kissinger, along with the majority of Nixon's reputable biographers of varying political stripes, all agree that suicide was more likely than any of these options, and I'll go with them over said article. If you could cite who wrote it, that would be nice.
Even if he wanted to, I don't think he could have. The military would not obey him, and he literally had no base in Congress left. Nixon was more aware than anyone of his lack of options by the summer of 1974 from an intellectual sense: he brought up resigning as early as April of 1973 when depressed, long before anyone else did. It was only his intrinsic aversion to giving up that literally kept him fighting until the end. Nixon was nothing if not a realist.