>In this case the actual motivations have been stated publicly by Trump a few years ago, they want the oil back. They will happily support whoever ends up in power so long as they hand back the oil rights.

That's obviously not credible, you can't profitably extract Venezuelan crude without US involvement. There's simply nobody else with the capabilities to do so. Venezuelan oil is particularly difficult to get out of the ground, it's tremendously difficult to extract profitably.