Prime Minister Malcolm Turnbull has issued a dramatic public humiliation of former prime minister Kevin Rudd, announcing that the government will not be nominating him for the role of UN Secretary-General on the basis that he is “not well-suited” to the role.

And on the face of it, there is little to fault Turnbull’s judgment. Kevin Rudd is a toxic egomaniac who can only function in a managerial sense in the extraordinary circumstances of a crisis, but who is entirely unable to operate in a normal management environment. If the UN Secretary-Generalship were decided on merit (which, of course, it never is), he would be lucky to get an interview. But that’s very far from the end of the story.

Turnbull has been forced into this decision by his own weakened position. He came within a couple of seats of losing the election and the right within his party have repeatedly signalled they are prepared to take him on. He currently faces a backbench revolt, partly orchestrated by the right, against the government’s superannuation tax changes.

It’s very likely that, given Julie Bishop’s support and the tradition of backing Australians internationally, had Turnbull been his own man, Rudd’s name would have gone forward — almost certainly to defeat, given Rudd’s chances were slim at best. But with a cabinet split, the issue turned into one about his leadership.

That’s the position that Turnbull now occupies — a wounded leader too busy looking over his own shoulder to worry about how he’s going to look to the electorate. And, regardless of the community’s mixed views about Rudd, this is a very bad look.