Well, Sam is absolutely right, of course, to say that a key issue was not addressed either by the published 'Overview' of the Government's Intelligence Review, or by my op-ed about it: do we spend too much on intelligence overall? 

It is an important question, because it is quite possible we do. As Sam suggests, if we want to know our region better, it might be more cost-effective to spend less on covert collection and assessment, and more on working with publicly-available material. Kennan was dead right about that, as about so much else.

But let me defend my omission on pragmatic grounds. While I agree with Sam that we might be spending too much on intelligence, in fact I do not think we are. We should certainly be spending more on public sources of all kinds (my conflict of interest here duly declared), but there are some kinds of information only intelligence can provide, and I think Australia's needs for those kinds of information justify the current spending, and would indeed justify a further increase, albeit allocated differently for the present budget.

The next question, obviously, is, 'which kinds of information?' The Government's Overview touches on this in a couple of places, including in an intriguing Appendix on 'Reasonable Expectations of Intelligence'. This is in many ways the strangest part of a strange document. It includes this notable sentence, 'The question the Review has asked is: What determines whether something is theoretically knowable?' Not often does a government review delve quite this deep. Alas, it seems they delved in vain, because we do not get a clear answer. Perhaps it has been held back in the classified version; if so, it's a sad loss to Western philosophy, which has been trying to sort this one out for 2500 years.

Seriously, though, the Overview does not even offer much of an answer to the more modest but more practical question about what intelligence can be expected to deliver. The Appendix explores the well-worn distinction between secrets and mysteries, and touches on Nasim Taleb's 'black swans', but I think it gets the wrong end of both these sticks.

There is meat for another post in all this, but for now suffice to say that the Overview misses two key points. First, covert intelligence is most useful in discovering what others are specifically trying to conceal. Second, its value increases as time-frames decrease, and vice versa. But even within these limits, there is a great deal to be found out. My hunch is that we need more, better-directed intelligence, as well as more blogs and think tanks.