WASHINGTON (AFP)- Secret US documents declassified on the eve of Saddam Hussein”s trial in Baghdad paint him as a cunning survivor who depended on guile and brutality to overcome challenges to his rule.

But the documents, which cover a period from 1975 to 2003 while Saddam held power in Iraq, also reveal US intelligence anticipated that the dictator”s overthrow could trigger sectarian divisions and leave the country vulnerable to Islamic militancy and Iranian influence.

The National Security Archive, a Washington-based independent organization dedicated to public access to government information, released the documents the day before Saddam was to go on trial in Baghdad for the 1982 massacre of 143 Shiites in the town of Dujail.

In nearly three decades of analysis and intelligence gathering, US government agencies had little idea of how to influence or depose Saddam and mostly hoped that he would be brought down by an internal coup, the documents show.

The declassified papers for the most part present detailed assessments of Iraq”s politics, military and economy with a grudging respect for Saddam”s ability to hold on to power through debilitating defeats on the battlefield, internal insurrection and grinding international sanctions.

&#34Saddam possesses a strong drive for power and an exaggerated view of his own capabilities which disposes him to assess optimistically his chances of success in any venture,&#34 said a CIA document from June 1982.

&#34Failure is a major blow to his self esteem, which places Saddam under substantial emotional stress,&#34 the CIA said.

Still, the analysis concluded that &#34Saddam is a fundamentally pragmatic man in touch with political reality&#34 and would likely rebound by blaming others for setbacks in Iraq-Iran war in the 1980s.

Eleven years later, another CIA report echoed that sentiment in a description of a micromanager who misses little.

&#34Imprisonment, exile, years of danger-filled underground existence, and numerous assassination and coup attempts have honed his survival skills. His 25-year reign as Iraq”s strongman has taught him self-reliance and wariness,&#34 it said.

However, US intelligence was unsparing in its assessment that brutal repression, often meted out through his family, was the underpinning of Saddam”s long dictatorship.

An August 1983 document about Baghdad”s ongoing campaign against Shiites in the southern Iraq marshes, while heavily redacted, nonetheless gives a picture of unforgiving oppression.

While carrying no dramatic revelations, the documents convey how Washington harbored fears that Iran and the Soviet Union might gain control over Iraq and its valuable oil resources.

A 1985 assessment notes that, though tenuous, there were signs of a warming toward the US by a Saddam wary of Tehran and Moscow.

In an echo of current developments in Iraq, US intelligence warned that overthrowing the Iraqi leader would lead to instability that could pull the country apart.

Saddam”s removal &#34could usher in an extended period of instability in Baghdad. His successors probably could not maintain Saddam”s system of tight control and any post-Saddam regime is almost certain to fall into factional fighting,&#34 said a 1985 CIA report on Iraq.

The report said that such infighting raised the chances of an Iran-backed fundamentalist Islamic regime coming to power — a widely anticipated possibility since the US-led invasion which toppled Saddam in April 2003.

A December 1993 analysis of Saddam”s survivability foresaw the same sectarian divisions now surfacing in Iraq, with Kurdish and Shiite communities keen to assert their autonomy over Sunni objections.

&#34The Kurds, for example, might be tempted to declare independence, while the Shias in the south would likely escalate their rebellion,&#34 it said.

Transition to a democracy, the 1993 report concluded, &#34will at a minimum require Iraq”s transformation into a federal state, perhaps even losing the Kurdish regions.&#34

While always hopeful of Saddam”s overthrow — US agencies gave him an even chance of being toppled within three years — the intelligence community nevertheless understood they would probably not know of a coup against Saddam before it happened.

&#34Any group of anti-Saddam conspirators that cannot keep their plot secret from US intelligence is also not likely to keep it secret from Saddam”s security services,&#34 they said in the 1983 report.