The bitterest sporting rivalry is still an act of peace. That is the contradiction at the heart of many great sporting events, even those played in a venomous atmosphere of hatred. It's true of all the desperate duels that have taken place between England and Australia, and even - perhaps especially - those still more highly charged matches between India and Pakistan.

We will get more of them as the World Cup unfolds before us, beginning with a recapitulation of the Ashes rivalry on Saturday and the latest round of the India-Pakistan opposition on Sunday. This group stage of the competition may be long-winded and ill-conceived, but there's no ducking the fact that it will open with a couple of spicy matches.

There are other rivalries to be found in world cricket: England, as former colonialist, against any one of the former colonies always carries added meaning; and these days India, as bullying financial masters of the game, against anyone is a fixture gradually rising in intensity.

But those more ancient rivalries are part of the warp and weft of cricket. Australia and England have been knocking each other down since 1877, when the snooty, effete born-to-rule gentlemen of England first took on the roughnecks and larrikins of Australia.

The first Test between India and Pakistan was not until 1952, but that doesn't make this a recent rivalry: it's the cricketing form of an opposition that goes back centuries; one that finds its best expression in cricket.

The essential nature of the England-Oz dichotomy is revealed by the question of captaincy. The Australian tradition is to pick the best 11 cricketers and then choose one of the blokes as captain because someone's got to do it, mate. Even if it's Ricky Ponting.

In England the tradition has been to appoint the captain and then build the team around him: elitism v egalitarianism. The English revere leadership as a match-winning quality all by itself, which explains the vast respect given to Mike Brearley: Test match batting average a shade under 23, won-lost record 17-4. The Aussies never saw the point of him - even after the traumas Brearley's team inflicted on them in 1981.

"Rivalry gives spice to any form of competition: but while the rivalry is a matter of bats and balls rather than bombs and bullets, such things can be cherished. Even if Sunday is the most venomous cricket match in the history of the game, it will still be an act of peace"

Australia have preferred a downright approach, damn the protocol and the politesse, with fast bowlers spouting aggressive nonsense and growing bravura moustaches. As is so often the case, when a bully gets bullied, the rules change: Bodyline remains the longest squeal in sporting history. It caused a serious glitch in the relations between the two countries - but even so, in a strange way, the row was a reflection of the bonds that unite the two countries. Cricket, even in these bitter circumstances, was an expression of a twisted kind of love.

How far is the same true of the rivalry between India and Pakistan? Here too there are contrasts of tradition. Pakistan - it's a generalisation, but sport loves a good generalisation - have come up with tall fast bowlers and mighty hitters, while India has preferred to look for a kind of magic in both batting and bowling.

The Indian batsman of the great tradition tends to be small in stature and cool in combat, playing shots that seem to defy the physical possibilities of cricket with the use of wrist and angle and timing. The archetypal bowler works with spin and mystery: no surprise that the first Hindi word to become part of general cricketing vocabulary is doosra, and the second, teesra.

Of course, these archetypes changed radically with the invention of one-day cricket and (for some) better nutrition. Kapil Dev led India to that historic World Cup victory in 1983 with swashbuckling athleticism, and since then the huge hitting required in the modern white-ball cricket has not found India left behind.

The on-pitch rivalries between these two cricketing nations have been suspended more than once, particularly when bullets in Kashmir have taken precedence over legspin in Lahore and cover drives in Delhi. Anglo-Oz sporting rivalry is a kind of banter between two nations that actually envy each other: Australia envying the sense of rootedness and tradition, the English envying the freedom and the opportunity for almost limitless self-invention that Australia seems to offer everyone who steps on its shores.

It's nice to think that India-Pakistan tension might one day be reduced to joshing about cricket, but there's a way to go yet - particularly as circumstances no longer allow international cricket in Pakistan. This was a devastating blow to cricket and its development and meaning across the world, far greater than is generally appreciated.

But perhaps the most important thing about the World Cup is that Pakistan are taking part. The real world is troubled every day by the threats and the deeds of fundamentalist Muslims, and most of the world hasn't quite grasped the point that the enemy of the world is not Islam but fundamentalism in all its Protean forms.

But here is a Muslim country, one with a complex and equivocal record with regard to religion, warfare and radical action - and yet it is represented in Australia by a bunch of sportsmen (people who are unable to play their home matches at home, the vast detriment of their sport) playing against a group of nations that includes an ancient and traditional enemy. Not fighting. Playing. You know - the thing that children do.

The mystery of sporting rivalries is not that they happen, for humans will strike up a rivalry with anyone who happens to be on the opposite side of the fence. It's that we can use these rivalries for the joyously trivial purposes of sport. Rivalry gives spice to any form of competition: but while the rivalry is a matter of bats and balls rather than bombs and bullets, such things can be cherished. Even if Sunday is the most venomous cricket match in the history of the game, it will still be an act of peace.