No-one was immune. His intelligence services spied on government ministers, business leaders, school teachers, journalists, judges. They spied on members of his own family. They even spied on each other. Under Saddam's leadership Iraq became a country in which everybody, without exception, knew that they were being watched at all times, and in which everybody knew that the price of disloyalty - real or perceived - was torture, imprisonment or death. This was the defining characteristic of his regime. Iraq was - notoriously - the 'Republic of Fear'.
The man who used fear so effectively was also its victim, however, as he showed in March 1991 after his forces had been expelled from Kuwait by an American-led coalition of half a million troops.
Iraq's conscript army deserted en masse and returned to their home towns and villages. Their arrival sparked a wave of anger throughout the country. In fourteen of the eighteen provinces, Saddam's regime collapsed. For six hours Baghdad itself appeared certain to fall into rebel hands. Saddam was a fugitive in his own land, hiding out in residential neighbourhoods. Wafiq Al Samurai, his deputy head of military intelligence, was with him. "He was afraid the allies were going to come all the way to Baghdad," Al Sammurai said. "He asked me whether I thought they would come. You could tell from the way he asked this question that he was afraid. Yes, he was afraid."
That the regime survived was down not to the US commander of the liberation of Kuwait, General Norman Schwartzkopf, who allowed Saddam's forces to continue flying helicopters throughout the country and let two powerful units of the Republican Guard, trapped in Basra, to return to Baghdad.
Saddam's fear sharpened his revenge. Iraqi opposition leaders say up to 300,000 people were tortured and executed in the repression that followed.
The experience of March 1991 left a legacy of bitter suspicion. The Americans, having liberated Kuwait, were now widely perceived in Iraq to have come to Saddam's rescue.
He had indeed enjoyed a long, complicated and mutually beneficial relationship with the United States. The coup that brought the Ba'ath Party, of which Saddam was a member, to power in 1963, was supported by the United States, openly welcomed by the White House and possibly even engineered by the CIA.
"There was certainly CIA involvement in that coup," said James Akins, who was political secretary at the US embassy in Baghdad at the time of the coup. "We had very close links with the Ba'ath Party before they came to power. I knew all the Ba'ath Party leaders. They were my friends. I liked them. When they came to power we saw it as a way of changing what had been a pro-Soviet regime in Iraq into a pro-American one. We thought they were the great hope for secular government in the Arab world."
For the White House, still reeling from the Cuban missile crisis of 1962, it was a relatively bloodless coup. "Sure, a few people were rounded up and shot," Akins went on. "But these were mostly communists and that didn't bother us."
At the time of the coup, Saddam was in exile in Egypt. Hundreds of young Ba'athists had fled to Cairo where they enjoyed the sponsorship of the hero of secular Arab nationalism, President Gemal Abdel Nasser.
Saddam had escaped Iraq after being wounded in an attempt to assassinate the then President Qassim Abd al-Karim, in 1959. The doctor who was called to treat him remembered a "yellowish boy" with a flesh wound to the calf. Saddam, he said, had dug the bullet from his own leg with a razor during the night.
The assassination attempt, and Saddam's subsequent escape, would become part of his personality cult. Much of his life story was embellished, but it is known that Saddam Hussein al-Tikriti was born in 1937 in the village of Ouija, in the plains of central Iraq, north of Baghdad. His father died before he was born and he was raised by his mother Subha al-Tulfa, and a number of mail relatives - uncles and cousins.
It was a society dominated by clan loyalty. His clan's home base, the town of Tikrit on the Tigris River about a hundred miles north of Baghdad, was unexceptional except as the birthplace of the twelfth century Muslim military leader Saladin, who defeated the Crusaders to retake Jerusalem for the Muslims and later saw off Richard the Lionheart. (The Saddam cult made much of this connection, spurious though it was as Saladin was not an Arab but a Kurd.)
The society he grew up in was violent and well armed. Some accounts say Saddam was given his first firearm at the age of eight. Another has him, at the age of ten, threatening to kill a school teacher who wanted to expel him. But, much more than violence, tribal loyalty was the overwhelming characteristic of the society into which he was born. He was to rise to power not by becoming prominent in politics or the military, but by harnessing the ties of kinship. One of the rebel officers who led the 1963 Baathist coup was Ahmed al-Hassan al Bakr, a relative of Saddam's. Bakr became prime minister and it was under his leadership that Saddam's stealthy seizure of power began, beginning with the building of security and intelligence networks answerable - and loyal - not to the state but to Saddam in person. For five years after 1963, Saddam Hussein lived on the fringes of the new political establishment, frequently falling out of favour and ending up in jail. The breakthrough in his political fortunes came in 1968 when a second coup brought the Tikriti clan to power. Bakr became head of state with Saddam as vice-chairman of the Revolution Command Council. he systematic violence and intimidation that was to keep Saddam in power began. Possible opponents were assassinated.
The Kurdish political leader Mahmoud Osman got to know him well during this period. "He told us, 'You have to kill some people, even if they are innocent, in order to frighten others'."
In the 1970s, Saddam Hussein, as Vice President, became head of Iraq's nuclear energy programme. In 1975 he made one of his rare trips abroad - to Paris - to visit the plant that was to supply Iraq with its first nuclear power station. He was welcomed in person by the then French prime minister, Jacques Chirac. Iraq and France signed an agreement which bound Baghdad to the terms of the Non-Proliferation Treaty; the plant would be for the production of energy only, strictly non-military.
In 1979, Bakr, in poor health, announced his intention to step down and hand power to Saddam. Some members of the RCC objected and demanded a vote. They did not live long. Saddam accused his fellow Ba'athists of conspiring against him, and of plotting with foreign powers. A meeting of the RCC was filmed in which Saddam is shown denouncing the alleged conspirators and being persuaded by terrified acolytes not to be lenient. Between a quarter and half the members of the ruling body were executed. It was at this time, too, that another distinctive feature of the Saddam regime emerged - a willingness to punish not only direct opponents and potential opponents, but members of their families as well.
Shortly after becoming president, Saddam summoned the chief scientists of his nuclear energy programme and demanded to know how quickly their work could produce a nuclear bomb. The chief nuclear chemist, Hussein al-Shahrastani, was the only one at the meeting who spoke up. "I knew that he was a dangerous man," Sharahstani remembered. "I just tried to explain to him that it was against our international commitment. He told me I was a good scientist and I should mind my own scientific work and leave politics to the politicians. After a while they came to my office and arrested me. I was tortured for 22 days and nights till I was paralysed."
Shahrastani spent the next 11 years in prison, much of it in solitary confinement, escaping only when the Saddam state began to collapse under the barrage of allied bombardment in 1991.
Saddam's use of terror explains why he was able to take manifestly disastrous decisions without a murmur of opposition from within the ruling elite. In 1980, he launched a war against neighbouring Iran, apparently convinced that the Islamic revolution that had taken place the previous year, replacing the regime of the Shah with the 'dictatorship of the clerics' led by Ayatollah Khomeni, had so weakened the Iranian state and army that a swift victory would be easy.
The Iran-Iraq War was to last eight years, cost hundreds of thousands of lives, and result in an inconclusive stalemate. It revealed two vital characteristics of Saddam's regime. The first was the possession of - and willingness to use - weapons of mass destruction. Iran defended itself against Iraq's technological superiority by deploying so-called 'human waves' - overwhelming numbers of young men, mostly conscripts, whose lives were sacrificed to repel Iraqi attacks. Many of these were killed by chemical weapons.
The second characteristic was an extraordinarily close - if covert - relationship with the United States. The Reagan administration perceived the ayatollahs' Iran to be the over-riding threat to US national interests, and it adopted Saddam as the best available counter-balance. The United States began to supply Baghdad with military assistance, including detailed satellite information about Iranian troops deployments.
In 1983 Reagan even sent a personal envoy to meet Saddam face to face. His name was Donald Rumsfeld. This relationship of tacit support continued despite the growing catalogue of atrocities associated with Saddam's Iraq. In the 1980s, believing that Iraqi Kurds in the north of the country were in league with Iran, Saddam forcibly removed hundreds of thousands from their land and razed their villages. In 1988 he used chemical weapons, killing 5,000 Kurds at the village of Halabja. Kurdish leaders turned to the west for help. Saddam's former friend, Dr Mahmoud Osman, went to Washington and found no-one wanted to listen.
"In '88 when we were gassed," he said, "the US was 100% with Saddam. I went in January '89 and in Washington I tried to see anybody in State Department. Nobody would agree to see me. They called me on the phone and said 'look we can't even talk about chemical weapons'. And why? Saddam was at war with Khomeini."
Charles Powell, then adviser to the British prime minister, Margaret Thatcher, concedes that "we were not as specific about the brutalities as we should have been - I don't think we made too much fuss. He did not seem at the time a threat to our interests".
By the end of the 1980s, Washington and the west had been turning a blind eye to Saddam Hussein's atrocities for more than a decade. It helps to explain why, when he invaded Kuwait in 1990, he appears to have believed he would get away with it.
The decision that was to change the strategic map of the Middle East - and, in the end, seal Saddam's fate, was made in late July 1990. Relations between Iraq and Kuwait had plummeted, partly because of a long standing border dispute (in which Iraq had a strong case) and because of a more recent disagreement over oil drilling rights. Iraq accused its southern neighbour of undercutting Iraqi oil production by overproducing for the world market, and by illegally 'slant drilling' from Kuwaiti territory into oil reserves beneath Iraqi territory. Kuwait dismissed Iraq's complaints.
Saddam summoned the US ambassador to Iraq, April Glaspie, to a meeting. She told him that the United States "took no position on Arab-Arab disputes".
It was a measure of how detached from reality he had grown that Saddam took this as a green light from Washington to invade. Saddam sent his troops into Kuwait without even informing the head of the Iraqi army, Nizar Al-Khazraji. "When he invaded Kuwait it became clear that he was unbalanced," al-Khazraji said later. "He did it without my knowledge and without the knowledge of the defence minister. When we met him three or four days later he told us he had kept it from us because if he told us in advance we would begin to make military preparations and that this would destroy his cover."
Wafiq al Sammurrai, who was then deputy head of military intelligence, claims to have drawn up detailed assessments of the military balance showing that Iraq could not hope to repel an allied attack but stopping short of recommending withdrawal from Kuwait for fear of the punishment such a recommendation would certainly bring.
"You could not tell him directly face to face to withdraw," said Sammurrai. "Nobody could say that. But we told him the situation was very dangerous, and that the military situation was not in our favour, that the Americans would destroy our forces and even our country. From our reports to him it was very clear what we thought. But you could not tell him to his face."
At no time during the campaign to liberate Kuwait did Saddam resort to the use of chemical or biological weapons, despite - as UN weapons inspectors were later to discover - the fact that plentiful stocks of both survived the allied bombardment. The reason why became clear later. James Baker, who was then the US secretary of state, had warned secretly that if Iraq used weapons of mass destruction against American troops, then the United States would respond in kind - a direct, implicit threat to use tactical nuclear weapons. Saddam had also received a secret Israeli threat to go nuclear. This was conveyed to Saddam by King Hussein of Jordan. The King's envoy had met the Israeli Prime Minister Yitzak Shamir in secret in London. Shamir threatened to 'go nuclear' within hours of any chemical or biological attack on Israel.
By opting to sit the war out, putting up token resistance only, Saddam snatched survival from the jaws of a crushing military defeat.
It was the worst possible outcome for the Iraqi people. The terms of the ceasefire the allies imposed plunged them into crippling poverty. The lifting of economic sanctions and political isolation was made contingent upon Saddam surrendering all weapons of mass destruction programmes - chemical, biological and nuclear. Throughout the first half of the 1990s UN weapons inspectors did, indeed, locate and destroy large quantities of weaponry - more, they claimed, than had been destroyed by military means during the war to liberate Kuwait.
But they also found themselves in a perpetual game of cat and mouse. Weapons of mass destruction continued to matter to Saddam because they were part of his repertoire of fear, to be used against the Iraqi people. He gave the impression that keeping stockpiles of chemical weapons - and hiding them from the inspectors - was, throughout the 1990s and beyond, more valuable to him than the lifting of sanctions. As we now know, he actually had no stockpiles left; but even the illusion of possessing them remained more important to him than sanctions.
Throughout the 1990s, the ruling family turned in on itself, growing more isolated, more venal and more paranoid. Saddam's two sons, Uday and Qusay, began to assert their claims to political power. Uday showed an appetite for depravity that shocked even those in his inner circle, committing crimes - including murder - with impunity. His temperamental instability turned even Saddam Hussein against him, and his younger brother Qusay - quieter, more cautious and calculating and politically more astute - emerged as favourite son and heir apparent. Then in 1995, the ruling family split wide open. Saddam Hussein's two sons-in-law, Hussein and Saddam Kamel, turned up in Jordan unannounced to claim political asylum, bringing with them their wives and children - Saddam's beloved daughters and grandchildren. They were pumped by western security services for information about Iraq's weapons of mass destruction. Then, as suddenly as they had arrived, they decided to go back. The head of King Hussein's private office, General Ali Shukri, was astonished that they believed that Saddam was willing to forgive and forget. "I told them" he said, "that if they went back they would be dead within seven days of crossing the border. I was wrong. They were dead with two days." Hussein Kamel and his brother had sat for decades at Saddam's right hand. They helped govern the Republic of Fear. And in the end it consumed even them. This was the nature of Saddam Hussein's hold on power: no-one - not even those who perpetrate the atrocities on his behalf - was safe.
Shortly before the 2003 invasion, one former secret police officer told me that many Iraqis were trapped by fear into working for a president they believed could be overthrown.
"Saddam is weak," he said. "He's really weak, because everybody is abandoning him. People inside want change but they are afraid. You ask me if I feel any shame because I worked for this regime for so long? I want to tell you something I have a family, a boy. He [Saddam] would kill him if he suspected me. But do you feel shame? The UK helped Saddam Hussein. America helped Saddam Hussein. He's your guy."
Saddam's fate was sealed by an event he had no control over and a crime committed by people who hated him as much as they hated the west - the terror attacks of September 11, 2001. As Fouad Ajami, the Arab-American scholar, writes today in News Review, Saddam "drew the short straw". America needed to hit out and Saddam's regime was "the perfect target of opportunity — menacing but in reality weak and isolated".
The three years since his downfall have been so painful for Iraqis that some hanker for the brutal certainties of his era. His arrest, trial and execution have taken place against a background of increasing mayhem in Iraq and recrimination in America over the mishandling of the occupation.
As he goes to his grave, however, it is right to remember that - before he seized power - Iraq could have been one of the richest and most stable nations in the region. It had everything: fertile agricultural plains, a highly educated urban middle class with strong links with the English speaking world, near-universal literacy, plentiful supplies of water and, of course, oil.
Saddam squandered that inheritance in the pursuit of personal power. The legacy he bequeaths his people is the near destruction of their country.
Allan Little is a former BBC correspondent in Baghdad
