They’ve put surface-to-air missiles on the roof of apartment blocks, created special lanes for Olympic limousines and effectively told us not to use half the Underground system for the first half of August. But the one thing they can’t do, it seems, is run basic security.

Four days ago, private security firm G4S announced it would be unable to cover 3500 security positions of the 10,400 they had contracted to provide. The government announced the Army would fill the slots.

Many of those troops are coming back from Afghanistan, and would otherwise be on leave. Some of them are being made redundant, as part of the swingeing Defence cuts.

Subsequent reports revealed a litany of abject failure by the company, the largest security firm in the world. Recruitment was chaotic, haphazard and last-minute, with applicants given training and then not rostered on, given hotlines to ring to register — only to find there was no record of their existence — those with security clearances excluded, and those who failed them signed on.

Further bad news followed: G4S could not guarantee  all the staff in public interface positions would be able to speak fluent English. Then whistleblowers started to come out of the woodwork, saying that elementary security procedures were being bypassed by under-trained staff.

G4S and the Cameron government tried to put a brave face on it, with the company’s CEO Nick Buckles saying it had been “fully transparent” with the government at all times — that is, on the enormous stuff-up that had endangered the very occurrence of the Games.

The government for its part was desperate not to acknowledge the stuff-up at all costs, with culture secretary Jeremy Hunt saying the drafting in of the troops showed the government had a contingency plan “and it was working as intended”.

Hunt — put on the spot during the Radio Four show Any Questions? — refused to apologise to the troops for ruining their leave, preferring to prattle on about how “willing they are to serve”. It didn’t go down well.

Two days into the crisis, David Cameron realised he had to be a little tougher and announced companies that failed to fulfil their contracts would be subject to penalty fees — Buckles had tried to claim the £50 million G4S would lose from sheer cost overruns was penalty enough.

The whole episode — which appears to be far from over — has been a triple disaster. It has exposed the authoritarian militarised security apparatus of the Olympics as little more than a sham, especially where a private company is concerned. It has given fresh ammunition to the notion that the Cameron/Clegg government is incompetent at the most basic functions.

Above all it has proved to be another blow against the idea renewed by the Cameron government that privatisation is a source of efficiency and savings. The Olympic debacle has occurred at the same time as the first announcements of privatisation of NHS services.

In Devon, children’s services will now be run by Virgin, because when it comes to your kids, what you really want is someone with the gravitas of Richard Branson taking care of business. Yet Virgin was far from the worst bidder — one other consortium included Serco.

Nor is it just the health services. The police force in Lincolnshire is contracting out its back office services on a £200 million contract to a company called … oh look, it’s G4S!

Yet, the Olympics disaster may well bring that process to a screaming halt. Late yesterday, it was revealed G4S had provided only 4000 staff, so further troops may be required. The Ministry of Defence has already announced  the 17,000 troops assigned to the Olympics are starting to disrupt normal deployment and the basic business of defence.

Nevertheless, despite all these failures — and the strong possibility Buckles may be forced to resign — the government continued to defend G4S, whining that the problem was not with the company but with the failure of those it contracted to turn up for work.

Still, whatever goes wrong, we still have the surface-to-air missiles on the roof. The building they’re located in houses the Australia Council’s London studio — so, at last, something launched from there will have an impact.

CLARIFICATION: The original version of this story said Serco was part of G4S. It is not and the copy has been amended.