Saddam Hussein's intelligence organization, among the most ruthless in the world, has systematically assassinated his rivals, some with rat poison.

It is used to suppress Iraq's 17 million people, creating a climate of fear and suspicion by encouraging children to spy on their parents and torturing those suspected of treachery.From Iraqi embassies around the world, it also hunts down Saddam's many enemies.

The powerful and dreaded agencies that make up the organization are controlled by Saddam and relatives from his hometown of Tikrit.

"No one dares ridicule authority any longer in Iraq because everyone is afraid," an exiled Iraqi scholar said in a recent book, "Republic of Fear," written under the pseudonym Samir al-Khalil. "The tone of political culture has become Kafkaesque."

Iraqi diplomats have been expelled from allied capitals in recent weeks. But Saddam's alliance with Palestinian guerrilla factions, reportedly including terrorist mastermind Abu Nidal, gives him other means to strike.

His security apparatus has three major departments:

- The Mukhabarat, or General Intelligence Department of the ruling Baath Arab Socialist Party, the monolithic political structure with Saddam at its pinnacle.

- The Estikhbarat, or Military Intelligence, which mainly operates abroad through Iraqi embassies.

- The Amnal-Am, or State Internal Security Department, which was restructured by Saddam in 1973 and had extremely close links with the Soviet KGB and military intelligence, as well as then-East Germany's intelligence apparatus, until the Cold War ended.

Other security departments include the police and the Interior Ministry and total more than 200,000 personnel. The most important is the intelligence section of the Presidential Affairs Department, which answers directly to Saddam.

The Mukhabarat, run by Saddam's half-brother, Sabawi Ibrahim, is the most feared. It has agents in all government departments and the armed forces as well as among Iraqi exile communities around the world.

Al-Khalil noted that the Mukhabarat grew out of the Jihaz Haneen, Arabic for "instrument of yearning," a secret organization Saddam created in the mid-1960s when the ruling Baath party was underground. The Jihaz Haneen played a key role in the 1968 coup that put the Baath in power.

Yacoub Yousef, a leader of the opposition Assyrian Democratic Movement, said at least 35 prominent Shiite Muslim clerics, as well as Baath defectors and Kurdish and Assyrian dissidents, have been assassinated by the Mukhabarat in recent years.

"Military men who defect carry in their pockets tiny pieces of paper with their names written on them so that if they're tracked down, their families can identify their bodies," Yousef said in Syria, Iraq's archrival in the Arab world.

"The regime's agents often disfigure their victims. Anyone looking for a missing son or brother has to go through the pockets of the dead looking for those slips of paper."

Mubdir al-Weis, secretary-general of the dissident Progressive Party of Iraq who fled Baghdad in 1970 for plotting against Saddam, said he escaped an assassination attempt in Cairo on Feb. 26, 1972.

He said 18 Iraqi agents were assigned to kill six dissidents, including himself, at 6 a.m. and catch a flight to Beirut an hour and a half later.

Al-Weis said one dissident, Col. Orfan Abdul-Kadder, was shot in the neck as he slept but managed to escape. The others, including former prime minister Aref Abdul-Razzak and former defense minister Rashid Mohsen, got away because the would-be assassins bungled the job.

But the Mukhabarat is not always so sloppy. Two agents killed Mahdi al-Hakim, a prominent Shiite cleric, in Khartoum on Jan. 17, 1988.One of the gunman allegedly was an Iraqi diplomat.

Al-Hakim was the 30th member of his family to be killed by the regime since 1974.

A few days after that, Abdullah Rahman Sharif Ali, an Iraqi businessman working in London, died after eating a restaurant meal sprinkled with thallium, a rat poison.

Yousef said that in June 1989 and February 1990, the Iraqis sent poisoned bread to Kurdish and Assyrian refugees in Turkey marked as "gifts from their families."

British authorities say the Estikhbarat has provided backup and weapons for Abu Nidal operations, including the attempted assassination of Israel's ambassador in London, Shlomo Argov, in June 1982. The Israelis used that as the pretext for invading Lebanon to crush the PLO.

The department's agents have also been blamed for slaying four Iraqi exiles in the United States in recent years. Last March, U.S. authorities expelled an Iraqi diplomat at the United Nations for plotting to murder two Iraqis.