Having just published Stephen Collins' reply to Rory's post, I'm going to pile on and offer my own critique.
But first let me point out that we have already received a number of emails from the bureaucracy and diplomatic community in support of Rory's position. Unfortunately, these were marked 'not for publication', so I want to encourage those readers in Canberra who feel constrained by saying that we are prepared to put aside this site's usual reluctance to publish anonymous comment.

So, to business, and I want to start by agreeing with Stephen Collins' introduction, and to put the case more explicitly: I think Rory is showing status quo bias. He is absolutely right to say that 'most of the world's problems demand cooperative responses', and that a certain level of secrecy is required to make this workable. But what level, exactly? Rory seems to assume that the pre-WikiLeaks level of secrecy was just the right one, and that Assange's organisation has busted open an arrangement that was working pretty well for world peace. I'm not at all certain that's right.
But even if Rory is right, that ship has sailed, and governments will have to learn how to cope in a WikiLeaked world. How are they doing so far? Rory is probably right that the leaked cables will just encourage governments to tighten security, and that this, in turn, will impede good policy and diplomacy. But another way of expressing this is to say that WikiLeaks is goading governments into taking self-defeating and counterproductive action.
How best to avoid this? One way is to shut down WikiLeaks, though that seems unlikely to succeed, and would just open up territory for imitators. So here's an alternative suggestion for the governments of the world: stop taking self-defeating and counterproductive action. Rather than tighten security in response to these leaks, why not loosen it? Instead of investing more in spooks and less in diplomats, as Rory thinks will happen, why not adapt to this new reality by shifting away from the presumption in favour of secrecy?
Maybe this would make life easier for the West's rivals. But the 'intelligence gifts' to America's rivals that Rory sees in the Wikileaks cables are tactical victories.
You can draw an analogy with the free trade debate. Opponents of free trade often make the 'level playing field' argument — there's no sense putting our own economy at risk by lowering tariff barriers if the other side won't reciprocate. Clearly it would be better if tariff protection was lowered all around, and it would be preferable if China's political system was just as transparent as America's. But whether the other side reciprocates or not, we can be strengthened when the barriers to the free flow of information and goods are lowered.
As to whether WikiLeaks is 'bad for journalism', I should say so! After all, WikiLeaks has comprehensively scooped the mainstream media. But let's be clear what Rory is talking about when he refers to 'journalism'. He's talking about a profession that is traditionally practiced inside a newspaper or TV station. But journalism is not solely a profession, it is an activity, and increasingly it can be practiced by anyone.
I would also like to hear more from Rory about what makes the WikiLeaks cables so special. The media has always trafficked in leaks, so if this one is so damaging, where does that leave the practice of leaking? Is all leaking bad?
My guess is that Rory's reply would have something to do with the 'indiscriminate' nature of WikiLeaks. But as Fergus just pointed out, only a tiny percentage of WikiLeaks' cables have been released so far, and its been done in consultation with major newspapers, who advised on any redactions that were thought necessary. WikiLeaks and the NY Times even sought State Department help for the redactions.
To close, I want to extend the free trade analogy a little. One of the greatest barriers to economic liberalisation is the fact that its victims are highly concentrated and vocal, and tend to be politically powerful. By contrast, the benefits of a free economy, while pretty overwhelming, are quite diffuse, so liberalisation does not have a strong political or lobbying base.
For instance, when a government proposes to lower farm tariffs, you will see farmers marching in the street and lots of sympathetic media coverage. But you won't see counter-rallies by consumers demanding that the government drop tariffs so that a litre of milk is 10 cents cheaper — after all, it's only 10 cents. Yet when multiplied by 22 million milk consumers, that 10 cents represents a huge efficiency gain across the economy. It's just that no single individual is likely to notice the difference.
Something similar is true for information. I'm sure Rory is absolutely right that the Northern Ireland peace process would not have survived a WikiLeaks dump, and those who are invested in the current system of classification will come up with lots of specific cases where leaks have caused damage.
By contrast, the case for greater freedom of information is more diffuse and less dramatic. Yes, the Daniel Ellsberg and Deep Throat examples demonstrate that leaks can have specific public benefits, but that may not be the main point. The more mundane but important point is that free citizens ought to have a really good idea of what governments are doing in their name. No specific piece of information will be transformative, but in sum the health of our society is enhanced when they know more.
It bothers me that, in his introduction, Rory's apparently sincere reference to the value of 'freedom and truth' transforms, in the very same sentence, into 'libertarian righteousness'. There clearly are people (and Julian Assange may be among them) who take pleasure in just 'sticking it to the man', but it is surely possible to take some satisfaction from the release of the WikiLeaks cables without resorting to such undergraduate anti-authoritarianism.
You don't have to be an anarchist to be in favour of greater transparency, just as you don't need to be an authoritarian to appreciate the need for occasional secrecy.
Photo by Flickr user John Kannenberg.