Is there a more hilariously unconvincing friendship in public life than that fabled one between Sir Alex Ferguson and José Mourinho? In the run-up toWednesday's Champions League clash between Manchester United and Real Madrid, the air has been thick with quacking about the managers' special relationship, which is apparently founded on mutual admiration for each other's abilities, respect for each other's prowess in the noble discipline of "mind games", all manner of self-deprecating joshing ... but we'll leave it there, shall we, on the basis that they clearly detest each other.

They are much too clever to say so, of course, but happily there are less Machiavellian – or less gullible – insiders who are perfectly willing to shatter the conceit. Sir Bobby Charlton, who might be expected to actually know about such things, was fairly succinct on the matter as recently as December. When it was pointed out to him that Ferguson admired Mourinho, his retort was withering. "He doesn't like him too much, though."

Well no. Much is made of the tea Ferguson and Mourinho took together at a Manchester hotel last year, but theirs is the most political of embraces, and all the more intriguing for it. The only time the two men ever seemed in genuinely matey accord was on the old "my enemy's enemy is my friend" principle, brought together in their mutual contempt for Arsène Wenger (who they have long since, rather pitiably, deemed unworthy even of that).

Those who buy into tales of Ferguson's equatorial warmth toward Mourinho are invited to run the mental YouTube clip of the erstwhile Porto boss dancing provocatively down the touchline at Old Trafford in 2004, or sweetly pointing out that his victory had been achieved on a 10th of the resources of Ferguson. Thank heavens such low-key ribbing was directed toward a man who famously does not hold a grudge.

Not that there is a shortage of compliments between the pair to lap up these days. Mourinho "can manage anywhere, absolutely", opines Ferguson of the man who would be king, while Mourinho always lets it be known that he calls Ferguson "The Boss". Sure he does. Especially when no one is listening.

As for what is really afoot, the picture remains opaque in parts. That Mourinho is politicking for Ferguson's job someday is no secret, but it is far from clear whether or not Ferguson wants him to have it (either in an après moi le déluge kinda way or the opposite), or whether or not Ferguson has even decided whether or not he wants him to have it.

So until such time as the mists part, I cannot read of either man praising the other without recalling the diplomat Metternich's comment on learning of the death of his arch-rival Talleyrand. "What did he mean by that?" he is said to have pondered. Admittedly, I can scarcely read of a single act by either man without wondering idly what they mean by it.

Take an interview with Neil Lennon this week, in which the Celtic manager explained how he had rung Ferguson and asked if he and his backroom team could come and take a look around United's Carrington training complex. "We're renovating the training ground at the minute," Lennon reports Ferguson as saying, "but I will come up and see you."

"Mm," I mused aloud over the breakfast. "I wonder what he meant by that?"

The likelihood is that Ferguson meant nothing other than to be nice, so even idle joking about an ulterior will doubtless draw frothing accusations of cynicism. And fair enough. Why CAN'T I hear Sir Alex Ferguson or José Mourinho say anything and not take it simply as the face-value verdict of one guileless everyman on another?

Either way, the true nature of the relationship between these most studied of chums is something far more riveting than a mere friendship. Some might trot out that Godfather quote about keeping your friends close and your enemies closer. More accurately, perhaps, it is that form of psychological warfare best characterised as killing with kindness.

There is a diplomatic manoeuvre nicknamed "The Fatal Hug", which theorises that one can neuter or even destroy an enemy by appearing to reach out to them. The political writer Joe Klein once wondered mischievously why the US does not just scrap all sanctions against Iran, open trading channels and name an ambassador. "It would drive them crazy," agreed an academic expert on the mullahs. "The thought of having an American embassy in Tehran again, with lines of people around the block, trying to get green cards ..."

At the time of writing Ferguson and Mourinho had yet to open official embassies up each other's backsides. But with more tales of their fine-wined buddydom to endure, one puzzle is why so many stoke this idea of the genuine friendship, when common sense, as well as sledgehammer hints like Charlton's, point to something much less trite. Either it is presumed that a market exists for tales of the two men's bromance, or a surprising number of people actually believe it.

If they wish to dine on red herring, then that is a matter for them. Yet surely the more compelling tussle is the Manchester United succession drama, the two men's blatant obsession with their place in managerial history and the sense that each man feels he needs to use the other from time to time, for reasons still tantalisingly unclear.