Why not? Trump doesn't give a fuck. Trump has never shown he has given fuck based on Trump University and the shilling jobs he has done putting his name on products that have failed. Also the whole not paying people for work thing.
If he strikes a deal and it's not a win-win such that it's only a win for him, then though that may not always be right, it's not necessarily disadvantageous for the winning side.
You're not bracketing up. If he works for a business, expect him to side with his personal well-being over the company to which he works. If he owns a business, expect him to side with the success of the business, community fallout be damned. If he governs a state, expect him to care a hell of a lot more about the success of the state he's governing. If he's president, lookout rest of the world. If he becomes leader of the planet, he might try to strike a good deal with alien life, but if he can't as such and only Earth comes out ahead, then it's a go.
You are saying he don't give a darn, well, the role he takes on is important, and you're not taking that into account. I find it hard to conclude that he's not going to act in the US's best interest because he didn't do so when it wasn't apart of his role to do so.