One of the most remarkable exchanges of letters between a prime minister and a departing cabinet minister was made public on Wednesday.
In the letters, Theresa May explains her belief that Gavin Williamson leaked information on a National Security Council meeting, and he insists he was not to blame. Mr Williamson was sacked as defence secretary.
If, as the prime minister says, Mr Williamson did not provide the same level of co-operation as other people who attended the NSC meeting, then that is damning. Why would he not?
The culprit had to be identified, because otherwise the other ministers present would have been implicated in the leak. And given that there have been few, if any, such comparable leaks from a cabinet minister in recent history, then the integrity of ministers, and the assumption of their ability to be trusted with such information, would be in doubt.
This is not, therefore, about freedom of the press, of which this newspaper is an emphatic supporter, as a title that has printed a vast array of news over almost three centuries, and nor is it about the validity of concerns about potential Chinese threats to UK security and infrastructure (concerns that are backed by compelling evidence). It is about the essential need for governments to be able to discuss security matters of the utmost gravity in guaranteed confidence.
Mr Williamson has shown other examples of bad judgement in his career, but nonetheless had positive qualities. Among the latter was his concern for veterans, to which the PM refers in her letter. He wanted to ensure that veterans will not be dragged through the courts in a disproportionate legacy focus. This is of course right and these concerns must stay at the heart of government. But if anyone at that level thinks they can force through an amnesty but continue sub criminal inquiries into allegations against the state such as police misconduct and no-one will notice, they should think again. Such a development would be a betrayal of the security forces. Once again Doug Beattie, right, is highlighting such a risk.