Twenty years ago today, one gunshot set off a political tidal wave, the effects of which still ripple through the Philippines.

On the hot afternoon of August 21, 1983, returning political exile Benigno 'Ninoy' Aquino was led off a plane at Manila's international airport by security officers from the regime of dictator Ferdinand Marcos.

As the group descended the portable stairs, one of the escorts drew a pistol and In 2001, the 'People Power II' uprising that deposed Joseph Estrada saw him replaced by a government mired in traditional politics and corruption.killed Aquino with one shot to the back of his head. Soldiers on the tarmac then opened fire and killed another man, who would later be presented as the 'killer'.

The gangster-style murder was meant to eliminate an alternative to Marcos, who was then ill. Instead, it became a defining moment for millions of Filipinos. Time seemed to stand still in Manila that day, as people absorbed the horror of what had happened.

Few could have predicted the actual course events would take. At the time, one anti-Marcos columnist dared to write what seemed a fanciful depiction of a future where the dictator was deposed and Manila's airport renamed Ninoy Aquino International. He was closer to the mark than most political analysts.

The murder led to a groundswell of unrest, sparked a series of massive demonstrations and culminated, less than three years later, in the 'People Power' uprising that chased Marcos and his family out of the country. And the leader who took over was Aquino's widow, Corazon, derided as a 'housewife' with absolutely no political experience.

Aquino's martyrdom helped give Filipinos the courage to throw out a despicable leader - something which they have done twice in 15 years. Unfortunately, his death gave no guidance on what to do afterwards. In 1986, the destruction of the Marcos dictatorship led to a restoration of the feudal oligarchy it had displaced. As president, Mrs Aquino failed to seize the opportunity to dismantle the elite-dominated political system.

In 2001, the 'People Power II' uprising that deposed Joseph Estrada saw him replaced by a government mired in traditional politics and corruption.

Ironically, apart from his widow, Aquino's family has played a big role in the non-improvement of politics. His brother and his sister banked on their relationship to him to win seats in Congress, where they closely allied themselves with the disgraced Estrada.

His daughter Kris, a flighty entertainer, has announced her intention of running for the senate. One of the slogans which 1983 gave birth to was 'Justice for Aquino, Justice for All'. Two decades later there has been no justice for Aquino, much less for any collective 'all'.

Although his killers are in jail, the actual masterminds remain officially unknown. There has been no punishment of the murderers, torturers and thieves who made up the Marcos regime - in fact, although the ex-dictator is dead, his family is back in power, still hanging on to the billions they stole.

Aquino's death certainly galvanised Filipinos into taking the fearful step of opposing a vicious government. But his sacrifice and the courage of millions have been wasted by a failure to follow through. In some ways, martyrdom and revolt are easier than the back-breaking, lengthy and numbing task of building a just political system.

Rather than dwell on these, politicians will now do the easy thing: promote Benigno Aquino to national hero, toss him up to a pedestal from which he can be safely and distantly admired, and reduce his value to just another calendar date to be memorised by schoolchildren.