I think part of why it’s so obvious that Donald Duck is an aquatic sociopath is that he is almost always paired with antagonists considerably smaller than he is. Where Bugs Bunny, for example, fought with Yosemite Sam or Elmer Fudd, and Mickey was usually paired with Pete when he had an antagonist, Donald fought bees and gophers—and children. He’s not strong enough or smart enough to enforce his will on the world as a whole, but he can by-Gods make life difficult for a pair of chipmunks.
Donald has a scale railroad. He’s done his whole backyard (this is from 1951, well into the suburban era of these characters) as a set-up for his trains, which he rides around in great contentment. All would be well were it not for a single tree he has just now noticed which is not to scale, so he digs it out. Naturally, it is the home of Chip and Dale, and this starts your standard war between them. At one point, things seem to have resolved themselves well enough, with the chipmunks moving into one of the scale houses—which they fit perfectly—but Donald cannot resist the opportunity to make their lives difficult by faking weather.
The short probably got its start from Walt’s own backyard railroad. The Carolwood Pacific Railroad was 1:8 scale, live steam, and ran on almost half a mile of track around his house and grounds. For a while, he even allowed visitors, though after an injury accident, it was closed to the public. At the time of this cartoon, though, he’d had his railroad for about a year. His lifelong fixation with trains is evident in both the parks and the subject matter of the studio from his lifetime. And Walt wasn’t the only one; even before Carolwood, animator Ward Kimball opened the Grizzly Flats railroad—a full-size, albeit narrow gauge, railroad that ran on 900 feet of track in his backyard.
The thing is, though, I feel as though Donald never starts with negotiation even when he clearly ought. Let’s ignore that this tree has obviously been there the whole time and he apparently just notices it in the opening minute or so of the cartoon. Further, he’s got to be aware that the chipmunks live there; if you only have one full-size tree in your yard, and you spend a lot of time in it, you can’t not know that there are chipmunks in it. Chip and Dale come up with a solution at the end that works for all parties, but let’s be real—the only reason the house doesn’t is that Donald chooses to pick on them.
Donald almost never wins these encounters. And that’s even in cartoons where we first see him dealing with the vagaries of inanimate objects and realize that he may well be trying to gain some control over a world that does often seem to have it out for him. The peaceable solution at the end of this one is practically unique, but focusing on that ignores that the conflict was completely avoidable and that Donald should be able to draw from his experience and not engage in the first place when negotiation is an option. Donald literally doesn’t seem to know how to handle situations in any way other than from a place of conflict, and that may be the clearest evidence of his pathology that Disney has ever given us.