TERRORISM : Case Against Muslim Cleric Could Blow Up in Prosecutors’ Faces : Despite his age, disabilities and lack of a lawyer, the sheik is not seen as an underdog in the bombing plot trial.

Scheduled to face trial in two months, the principal defendant in the next U.S. terrorism case is blind, has heart trouble, suffers from diabetes, does not speak English and has no legal training. Yet he insists on serving as his own defense lawyer.

What chance does radical Muslim Sheik Omar Abdul Rahman have of succeeding against charges that he was the spiritual leader of a group of 13 Islamic militants bent on blowing up the United Nations building and other Manhattan landmarks?

All signs point to better-than-average prospects. Try as they might, investigators have not been able to tie Abdul Rahman clearly and tightly enough to the bomb plot, in the opinion of some federal law enforcement officials.

Without such direct links, the 56-year-old cleric may succeed by arguing he is the victim of overzealous federal prosecutors who are searching for a motive by twisting the meaning of his religious speeches and whose case against him is so weak it relies primarily on recordings of his own inconclusive private utterances--words secretly taped by a government informant who has shown himself to be less than reliable.

“I think we’re doing a high-wire act in prosecuting Rahman,” one law enforcement official said. “There’s more evidence against most of the others, but trying to tie in Rahman with them could bring down the entire case.”

Circumstances had not always seemed so grim to investigators. Members of the U.S. attorney’s office in New York breathed a sigh of relief in June when the most important defendant besides Abdul Rahman signaled he wanted to cooperate with the government and possibly testify against the sheik and others.

The decision by Siddig Ibrahim Siddig Ali, a 33-year-old Sudanese immigrant, seemed to assure that prosecutors would have a key witness inside the alleged bombing conspiracy who could strengthen their case and allow them to reduce their reliance on the informant, Emad Ali Salem, the sheik’s former bodyguard who voluntarily helped the FBI.

Siddig Ali, after all, had been the sheik’s translator, his confidant and his foremost aide, as well as the defendant who was Salem’s most crucial contact.

But after several weeks of negotiations over the summer, the deal with Siddig Ali fell through--for reasons that are not entirely clear. So once again the government has been left to rely on the erratic Salem. On some of the tapes, Salem seems to be the one encouraging criminal acts, leading attorneys for some defendants to believe they can convince jurors that their clients were illegally entrapped.

Salem has presented prosecutors with another problem. Besides the body recorder supplied by the FBI, the former Egyptian army colonel used his own recorder to covertly tape conversations with his FBI handlers, drawing them into making embarrassing or improper remarks on some occasions that inevitably will become part of the trial.

For instance, transcripts of those recordings provided to defense attorneys show Salem claiming that he alerted the FBI beforehand to last year’s World Trade Center bombing and that the FBI had failed to act. Federal officials, however, have sought to dismiss his claim as an empty boast intended to inflate his own importance.

Abdul Rahman, imprisoned more than a year since his indictment, is planning to base his defense largely on claims he was only exercising his right of free speech in sermons at his Jersey City, N.J., mosque and in counseling sessions with his spiritual followers, many of which Salem recorded. Like all his co-defendants, the sheik has pleaded not guilty to government charges that he sought “to levy a war of urban terrorism against the United States.”

Some high-ranking law enforcement officials, in fact, were divided last year on the wisdom of charging the sheik as leader of the alleged conspiracy, federal sources have told The Times, because they thought the case against him was weak. High FBI officials were said to have argued against charging the cleric, preferring instead to limit the indictment to Siddig Ali and other defendants who had been photographed by a hidden FBI camera while they mixed chemicals in a Queens, N.Y., garage in June, 1993.

Most of the acts charged in the alleged conspiracy occurred after the bombing of the World Trade Center in February, 1993, in which six people were killed and more than 1,000 were injured. In that case, four people were convicted earlier this year and have been sentenced to 240 years each in prison.

Sheik Abdul Rahman and his followers basically are under indictment on charges that they conspired to blow up the United Nations building, the Lincoln and Holland commuter tunnels and to assassinate U.S. and foreign political leaders, including Egyptian President Hosni Mubarak. Their supposed motive: to punish the United States for its support of Israel and the current rulers of Egypt.

The sheik, an avowed enemy of Mubarak’s government, is no stranger to court proceedings and has successfully defended himself before. More than a decade ago, he was acquitted in Egypt of charges that he inspired the assassination of President Anwar Sadat in 1981.

He left Egypt after being charged there in 1989 with inciting an anti-government riot. Arriving secretly in Khartoum, he obtained a visa in 1990 to enter the United States, reportedly with help from CIA agents to whom he had supplied information.

Some people who attended meetings with Atty. Gen. Janet Reno said she overcame her own misgivings and those of some subordinates by endorsing conspiracy charges against the sheik in August, 1993. Reno believed this was “a case that had to be prosecuted” to show the nation’s resolve in preventing domestic terrorism, the sources said.

Abdul Rahman chose to act as his own defense counsel after U.S. District Judge Michael B. Mukasey denied the sheik’s request to be represented by New York attorney William Kunstler, who long has championed radical causes. Mukasey ruled that representation by Kunstler would pose a conflict of interest because the well-known lawyer already had other clients in the case.

But attorney Emanuel A. Moore of Hollis, N.Y., who has been appointed to serve as a legal adviser to Abdul Rahman, says the charismatic sheik is an outstanding scholar and seems fully capable of handling his own case, even though he lacks legal training.

Government attorneys plan to cite speeches in which Abdul Rahman talked of the duty of all Muslims to sacrifice themselves for jihad , or Islamic holy war, and called upon his followers to “strike terror into the hearts of the enemies.”

Moore said he finds it troubling that prosecutors would use the sheik’s public speeches and books “that you can buy on the streets of New York City” to bolster their contentions that he was responsible for terrorist acts by his followers.

The sheik himself has told the court that the case against him is based on nothing more than his expression of political views, which he insists are protected by the Constitution. But Judge Mukasey said speech is not protected by the First Amendment “when it is the very vehicle of the crime itself.”

In a recent ruling, the judge said that “even speech that includes reference to religion may play a part in the commission of a crime.”

The government, however, may be hard-pressed to show Abdul Rahman was the driving force for terrorism as he is pictured in the indictment.

For example, among the 150 hours of conversations recorded by Salem is one in which Abdul Rahman actually counsels against an attack on the United Nations because “it would muddy the waters for Islam.”