Salutes, it seems, come laden with significance. Michelle Grattan has written at length about Kevin Rudd’s salute to Dubya. David Crowe believes the salute somehow, like an errant scratch of the nose at an auction, bought Australia ownership of the war in Afghanistan. Insiders discussed it at length before concluding it wasn’t significant.

You have to be careful how you wave your hand around near world leaders, apparently.

I observed another salute, once, from Kim Beazley, during his second stint as Opposition leader. I sat in the advisers’ box in the chamber while a division proceeded over the passage of some Bill. Beazley entered the chamber, approached the Speaker’s chair and grinned cheerily at the acting Speaker, a Government member, then snapped a smart salute to him. It was the greeting of a good-humoured gentleman, of the decent bloke everyone, even his opponents, knew Beazley to be.

It also looked, somehow, in some inexplicable way, entirely un-Prime Ministerial.

This is not to say Beazley wouldn’t have made a fine PM. But Australia’s recent history shows that the only people who get the top job are those who are obsessed with it, who lust after it with every fibre of their being, and don’t care what price they pay to get it. Keating and Howard were prepared to tear their parties apart to get the leadership. Fraser was prepared to drive the country to the brink of a constitutional crisis. Hawke was happy to crush the ambitions of Bill Hayden beneath his own messianic self-belief.

And you only have to look at Kevin Rudd to know how much he wanted the Prime Ministership. In some ways he’s even scarier than any of his predecessors. And maybe, to really indulge in speculation, I reckon you can see the beginnings of the same intensity in the cold malice with which Julia Gillard watches the Opposition in Question Time.

To lack this quality of total political self-obsession is no failing – certainly not personally, and not even politically. There is nothing wrong, even in public life, in seeking to serve in ways that do not divide and wreck. For a long time, like a lot of others, I criticised Peter Costello for being gutless. Perhaps, more accurately, he simply isn’t the political sociopath that we seem to elect in this country.

Nor is Brendan Nelson. Nelson, observed up close, seems a decent, intelligent, affable chap, even if some of his ideas are pretty strange. But, while he’s always been ambitious, he hasn’t got that real hunger that marks him out as deadly serious about becoming Prime Minister. Whether he is more analogous to Beazley or Simon Crean probably doesn’t matter much. Neither wanted the job badly enough, and nor does he.

It’s unnecessary to point out who does on the Liberal side. But Turnbull’s progress as shadow Treasurer has hardly been an unqualified success. The hunger isn’t enough, of course. You need luck and timing, and experience too. It may be his fate to time his political peak with the age of Rudd. But his party will have a better chance of ending that age if it is led by someone who is utterly obsessed with winning. Such people never die wondering.