It took two natural disasters for China to turn things around in its Olympics year. The devastating earthquake and the authorities' swift and - to the outside world, at least - compassionate response was in stark contrast to the callousness of the Burmese Government's treatment of its untold and unable to tell typhoon victims. In one fell swoop images of Tibetan monks being beaten were replaced by those of generals in unfeasibly large caps. The world had a new polecat. Bring on the Games.

Nearly 40 years ago another public relations coup also cast China in a new light. The story was told in Garry Richardson's excellent The Ping-Pong Diplomats (Saturday, Radio 4). In 1971 China had been shut away behind the bamboo curtain of Mao's Cultural Revolution for five years. Nobody got in, and only vague stories of terrible atrocities got out.

But Mao was worried. Relations between Beijing and the Kremlin were at an all-time low. China could do with a powerful ally to stave off the possibility of war. At the same time President Nixon was looking for a way out of the war in Vietnam, and fearful that growing Chinese involvement in Laos might escalate. What to do on both sides, without losing face?

The answer came: ping-pong. At the 1971 World Table Tennis Championships in Nagoya, Japan, a leading member of the American team, a long-haired teenage rapscallion called Glenn Cowan, missed the team bus to the sports hall and bummed a lift off the Chinese team. At the end of the journey China's leading player, Zhuang Zedong, presented him with a gift, a silk-screen image of the Huangshan Mountains. The following day Cowan reciprocated, giving a T-shirt with “Let it Be” printed on the front.

Pictures of the two men flashed around the world. Mao saw them. He knew a PR coup when one came up to him and gave him a crappy old T-shirt. An invitation was made for the US to send a table tennis team to play in China. Nixon accepted. Being Nixon he didn't tell anyone, including the State Department and the CIA.

And so, in April 1971 the first Americans allowed into China for 22 years played a series of exhibition matches. Two members didn't make the trip - one, because he was from South Korea and was nervous; the other because it clashed with a holiday in Hawaii. The rest were briefed on how to comport themselves: they were told not to call the Chinese “Chinamen” and that was about it. The Chinese players had been told not to play too well, and so everyone came out on top. Not least international diplomacy. America lifted its trade embargo on China and, in 1972, Nixon paid a visit. A small gesture had had enormous results.

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