Leading article: Questions that remain after a resignation long overdue

Alastair Campbell used to say that if the same story ran for 10 to 12 days you knew you had a real crisis management issue and not a temporary frenzy.

So it came to pass with the departure of Liam Fox. What began as criticism posed by the Charity Commission of Atlantic Bridge, a charity founded by Mr Fox and run by his close friend Adam Werritty, grew into a full-blown Whitehall scandal culminating in the Defence Secretary's resignation yesterday.

Actually, but for the underlying seriousness of the episode, Whitehall farce would be more appropriate. Because the more we learned about the mysterious Mr Werritty – and despite our knowledge being expanded an awful lot in the past week he remains just that, with unexplained connections and questions raised over his personal finances – the more ludicrous and lurid the whole affair became.

There was Mr Fox, holder of one of the highest and most sensitive posts in the land, responsible for the oversight of our armed forces and military provision, privy to all manner of detail concerning national security and possible defence contracts, being accompanied on his official trips and in ministerial meetings by someone whose only qualification for attendance appeared to be that he was the best man at Mr Fox's wedding.

That in itself was incredible enough. But the repeated presence of Mr Werritty during engagements undertaken by Mr Fox took on a darker complexion when it was revealed that business executives and foreign dignitaries were under the impression that he was there as an official adviser to the minister. That colour became darkened further when it emerged that Mr Werritty presented himself to others as a political and business strategist – surely code for lobbyist – and that he was being funded by private wealthy backers.

Suggestions were made that the two men's friendship was more intimate still, but frankly, whatever its nature, that does not get to the heart of why Mr Fox had to go (although it would raise doubts about his truthfulness in response to the positive vetting that he must have had on being proposed as Defence Secretary and the way in which he sold himself to a voting public as being a happily married heterosexual).

No, the real concern centres on the inability of Mr Fox to see the potential for conflict of interest that might arise if a member of his most trusted circle also had external, defence-related business interests. Put simply, it was plain wrong that Mr Werritty should have enjoyed the level of access that he did without proper clearance and checks being made.

Given the succession of controversies surrounding the decline in public standards, it is shocking that Mr Fox's own antenna did not signal anything untoward. Worryingly, as the facts became more evident, the Prime Minister's sense of propriety also deserted him. Mr Cameron's loyalty to his ministers is in many ways admirable, but it has to be asked why he stood by his colleague long after enough evidence had emerged to make his position untenable. This was not a moment to put party before country.

The most alarming issue to arise from the debacle is: just how many other Adam Werrittys remain? Are there other shadowy characters in Whitehall departments who also enjoy the same privileges? And where was the normally scrupulous civil service in this?

If it's true that members of the MoD warned of Mr Werritty's proximity to Mr Fox, why weren't they listened to? What does that say about the nature of David Cameron's Government? At best, the rise and fall of Mr Fox creates an impression of recklessness; at worst, lackadaisical gives way to deliberately corrupt. One is better than the other but neither is good enough. It's not only Mr Fox who has some explaining to do; Mr Cameron needs to provide some urgent and full answers.