In 2003, Taiwan's former First Lady was named one of Time magazine's Asian Heroes. Now she could face jail time. Her Thai counterpart is doing no better, having been sentenced to three years for tax evasion, without her other half. Between a graft indictment and a divorce-of-convenience, Asia's First Wives have shown that they are no mere tai tais or ladies of leisure.

They are not Laura Bush, forever smiling, forever supportive, a silent ornament next to her bumbling husband, George. Neither are they Hillary Rodham Clinton, outspoken, aggressive, a scene-stealer, as much a liability as an asset to the charismatic Bill. They are constrained by culture and tradition to be subservient to their men. Yet they, too, have a free hand to expand their power and influence. Given the right conditions, they can change the fate of nations and affect the life of untold millions. They are the First Wives of Asia.

Of the many past and present First Wives – the spouses of Kings, Presidents, Prime Ministers and Chief Executives – the most infamous are from China. Soong Mei Ling helped Chiang Kai-shek extend his ineffectual rule and delayed China’s resistance to the Japanese invasion. Jiang Qing helped Mao Zedong launch the Cultural Revolution. Both had the blood of millions on their hands.

Soong was a rich man's daughter, educated in the US; Jiang, a third-rate actress with little education. But both came to power under the same set of conditions: a husband who was a dictator in all but name; a country ruled not by law but by personal authority; and the absence of any effective counter-measures that could check their ascendancy.

China is still recovering from the horrors of the past. It has erected safeguards to prevent a repeat of the Soong/Jiang eras. It is telling that the current crop of First Wives – Mrs Deng Xiaoping, Mrs Jiang Zemin and, the incumbent, Mrs Hu Jintao – have lived relatively quiet lives. China has made it impossible for them to grow into another Soong Mei-ling or Jiang Qing.

But not in other countries. The Philippines, which sent Imelda Marcos and her dictator husband Ferdinand fleeing in 1986, has welcomed the widowed 'Steel Butterfly' back with open arms. Forgotten are their excesses, the plane-load of gold they were supposed to have carried with them when they fled to Hawaii (so heavy was the load that the plane had to make many refuelling stops), and the misery of life under them. If Imelda, 77, and still the world's most famous shoe collector, is too old to rebuild her power base, there are many waiting to take her place

Ditto for Indonesia. From the 1960s to 1990s, General Suharto ruled Indonesia with an iron fist, and his wife, Ibu Tien, grabbed money with an open hand. Madam Suharto was known as "Madam 10 per cent", both a play on her name and a reflection of the commission she exacted. The first couple had six children, and all six inherited their mother’s insatiable greed. When Madam Suharto died of a heart attack in 1996, her children went all out to take money and peddle influence. When Indonesia was hit by the Asian Financial Crisis in 1997, violence erupted. Suharto was unceremoniously ousted. One of his sons went to jail.

Nine years and five presidents later, corruption still runs amok in Indonesia. The incumbent, Susilo Bambang Yudhoyono, is said to be relatively clean. But he has installed his wife, Ani Bambang, as the vice chairman of his political vehicle, Democratic Party. The First Wife of Indonesia is also the first degree holder — she has a political science degree from the local Merdeka University — to occupy the presidential palace. The daughter of an influential army general, she has yet to put a foot wrong. But both she and her husband are new to power. Will she become another Ibu Tien when they are more settled? Only time will tell.

Americans like to think that democracy solves all ills. In Asia, Thailand, Taiwan and even Cambodia hold regular elections. But that does not stop the unelected First Wives from wielding power. Potjaman Shinawatra of Thailand chooses cabinet ministers for her husband, Thaksin. Bun Rany Hun Sen runs the Red Cross in Cambodia, and much more besides. She is so powerful, it is said that she can get away with anything but murder. Or perhaps even that. (Madam Hun Sen was accused by a French magazine of arranging the killing of her husband’s actress mistress. She did not take any action against it.) The wheelchair-bound Wu Shu-jen made Chen Shui-bian the President of Taiwan, but her addiction to money turned his six-year administration into corrupted machinery. Now exposed by the opposition, both she and Chen may come down in flames.

It is only in Hong Kong and Singapore, former British colonies which inherited their former master's legal system, that the First Wives are not involved in politics. But neither Selina Tsang nor Ho Ching spends their days opening flower shows or cutting ribbons. Selina, an artist, is Hong Kong Chief Executive Donald Tsang’s best lobbyist in Beijing. Ho, a civil servant before her marriage, now runs the huge investment firm Temasek, owned by the government of Singapore, of which her husband Lee Hsien Loong is the Prime Minister.