He has said this before. His response to allegations four years ago that right-wing elements in the security forces had embarked on a violent campaign to destabilise the democratic process was that he would 'cut to the bone'. He failed badly then, and one hopes he will not fail again.
The question is whether Mr de Klerk, by taking action much earlier, might not have avoided this last-minute panic - all these people being torn to pieces on the streets of Johannesburg. Nelson Mandela never tires of reminding him that he has been slack in grappling with the extreme right, and with the threat from within the security forces.
The commandos of Eugene Terre-Blanche's Afrikaner Resistance Movement (AWB) have been holding paramilitary training exercises openly, putting on special displays for the television cameras, admitting their objective was to wage war against 'the Communists' of the African National Congress. There has always been buffoonery in the AWB and, perhaps, Mr Terre-Blanche's overgrown boy- scout commandos never represented much of a threat. But operating within the folds of the AWB have been cells of fanatics driven by the same paranoia which inspires Mr Terre-Blanche's oratory.
The police have taken action recently against some extremists, but more often they have been released after brisk, gentlemanly, interrogation. The security forces have never pursued the extreme right with the zeal they displayed against the ANC in the Eighties, when the organisation was banned. To which they might reply, with some justice, that the AWB has never been illegal.
Where the government has a lot to answer for is in its failure to explore the countless allegations made in the press about a 'third force' within the police and army. More so, given the findings released last month of the commission of inquiry into political violence, chaired by Judge Richard Goldstone. The judge found conclusively that a 'third force' existed, and that a security police colonel by the name of Eugene de Kock had planned the killings of commuters on trains, had trained Inkatha hit- squads and provided them with guns, and had deployed his own hit- squads within a clandestine police unit he himself led to kill black civilians. Judge Goldstone implicated three police generals, whose only punishment has been suspension from duty on full pay.
The most serious question that remains to be answered is why the South African Cabinet approved a 1.2m rand ( pounds 280,000) pay-off to Colonel de Kock on his retirement from the police a year ago. The only answer one can come up with is that he received the money to keep quiet. Presumably the fear that he might sing explains why he has not been arrested.
It is people with the expertise of Colonel de Kock who are carrying out the present terror campaign. No ordinary AWB farmer, no amateur right-wing loony, would be capable of planting car bombs in the middle of cities and getting away with it.
Why, then, has Mr de Klerk not reined them in? Because he feared what they might do, if he antagonised them. Because he calculated he would lose support in the white community and risk unleashing a full-blown civil war against the democratic process. He felt, above all, that he had to keep the security forces on board. Which he has largely done.
Maybe his calculation was right. Maybe things would be far worse today if he had acted with conviction against the right wing. But don't doubt for a minute that if 15,000 whites had died in political violence in the last four years instead of 15,000 blacks, heads would have rolled long ago.