I don’t think that most republicans believe they need Greenland for security reasons, but so what? They might as well, or it would be better if they did at least believe this, because the person they voted for and are still supporting is acting like a lunatic. And they are cheering him on, or at least condoning it.

I do believe that that plenty of republicans like Trump threatening former allies like a big and strong businessman/mob boss would do. The same goes for those who think they should grab Greenland for the resources, or just because they can.