The prolonged dispute between Deputy President Jacob Zuma and National Director of Public Prosecutions Bulelani Ngcuka recalls the conundrum about whether the power of immovable stone will prevail over that of the irresistible force or vice versa.

In the quarrel - that threatens to fracture the usually unified public facade of the ruling ANC ahead of next year's general election - Zuma broadly represents the immovable stone and Ngcuka the irresistible force. The two men, however, occasionally act in ways that signal the need not to be too rigid in typecasting them as immovable and irresistible.

Zuma has launched counter-attacks that indicate he is not confined to stonewalling in the face of assault. Some of his public accusations against Ngcuka and the investigating Scorpions are offensive rather than defensive. The same rider should probably be pinned to his deferred application for a High Court injunction ordering Ngcuka to hand over the original copy of an encrypted fax in which he, Zuma, purportedly solicited a R500 000-a-year protection fee from a beneficiary of the arms deal, the French armaments company Thales (aka Thompson-CSF).

Ngcuka's reaction to the allegedly defamatory affidavits that accompanied Zuma's urgent court application, in which Ngcuka is accused of grossly abusing his power, is essentially defensive. His decision to sue City Press for an article casting aspersions on his political integrity, and thereby boosting Zuma's position, appears to be defensive as well. The offending article states that Ngcuka was investigated in the mid-1980s during the ANC's Bible Project that sought to unmask apartheid government agents within its rank.

These qualifications, however, modify without refuting the immovable stone versus irresistible force metaphor and its deadlock connotations. The impasse configuration remains even when the conflict between the men is viewed through a different intellectual lens.

Joel Netshitenzhe, head of government communications and a leading ANC political theorist, argues that the government has no option but to take Zuma at his word and accept his repeated and categorical declarations of innocence in the face of the serious allegations against him (The Star, August 28).

For the government to insist on the resignation of senior leaders against whom serious allegations have been made would, Netshitenzhe argues, establish an untenable precedent. It would allow spanners to be thrown in the government works by anyone, anyhow and at anytime, and thereby impede the machinery of good governance.

Noting that trust between its leaders served the ANC well in difficult times in the past, Netshitenzhe contends that the tradition should be upheld in the present awkward situation. He reminds the public that, like less exalted South African citizens, Zuma is entitled to the presumption of innocence until and unless guilt is proved.

There is, however, a countervailing view to Netshitenzhe's perspective, an important component of which is that Zuma is not an ordinary citizen and that he, as South Africa's deputy president and the head of the nation's moral regeneration campaign, must, like Caesar's wife, be above suspicion.

The allegations against him can neither be perfunctorily dismissed as malicious gossip nor rationalised away as the slurs of his political enemies. They emanate from the National Prosecuting Authority and the Directorate of Special Investigations, who, presumably, would not have investigated the financial affairs of the deputy president unless they believed they had good reasons for doing so.

As Zuma is entitled to the presumption of innocence until and unless he is proved guilty, so, too, Ngcuka and the Scorpions should be presumed to be fulfiling their constitutional duty to investigate suspected corruption, unless the contrary is proved conclusively.

Zuma's sense of grievance at Ngcuka's modus operandi is understandable. While deciding not to prosecute him for corruption because the prospects of success are not strong enough, Ngcuka has nevertheless condemned him in the public mind by:

stating that there was a prima facie case against him, which legally means there is evidence that establishes a presumption of fact against him; and

sanctioning publication of the draft charge sheet against his financial adviser, Schabir Shaik, the details of which reflect adversely on Zuma as much as his adviser.

But Zuma should perhaps tell the public why he retained Shaik as financial adviser after he assumed executive positions in the government when he knew that Shaik actively sought business contracts from the government at provincial and national level. In doing so, he put himself in a position that he should have avoided if he wanted to be above suspicion.

Now, however, with the shadow of impropriety hanging darkly over him, he is a mere proverbial heartbeat away from the lofty and powerful position of president.

While it is true that the deputy president does not automatically take over as president in South Africa in the event of the premature death, incapacity or impeachment of the incumbent president, as Lyndon Johnson did in the US in 1963 after the assassination of John F Kennedy and as the unelected Gerald Ford (who had replaced the disgraced Spiro Agnew as vice-president in 1973) did after Richard Nixon's resignation in 1974.

But, as South Africa's deputy president, Zuma would be well positioned as a contestant to replace President Thabo Mbeki if an untoward contingency ended Mbeki's tenure prematurely. For Zuma to take over as president with the suspicion of venality still lingering over him would be inimical to South Africa's reputation as a young democracy committed to the excision of corruption wherever it might exist. It is a risk to which the country should not be exposed.

Zuma can, however, break the deadlock and establish his innocence by asking Mbeki to temporarily relieve him of his office, to enable him to take his case to parliament and by urging his purported French armaments interlocutors in the alleged solicitation of a protection fee to subject themselves to parliamentary interrogation.

With acknowledgement to The Star.