Iraqi President Saddam Hussein is a bold, ruthless leader who is determined to become the leading power in the Persian Gulf, in the view of many U.S. and Arab analysts. But they also note that the Iraqi has a tendency to overreach, placing himself in what are sometimes untenable military positions.

Both aspects of Saddam have been evident throughout his career: in the 1980 invasion of Iran, the 1984 decision to launch the tanker war in the gulf and the subsequent missile war against Iranian cities, and in the decision to use poison gas in the war.

The start of the Iraq-Iran war may be the foremost illustration of Saddam's tendency to bite off more than he can chew. After a border squabble with Iran during the spring and summer of 1980, Saddam made a precipitous decision to invade Iran. His troops surged across the border in September 1980, much as they stormed into Kuwait last week. But by October 1980, the Iraqi army was bogged down in southern Iran, unable to take key objectives. By 1984 and 1985, his troops were being pushed back across the border into Iraq.

What makes Saddam especially dangerous, analysts say, is that rather than compromise or retreat when he gets in trouble, he tends to double his bets. That is what happened during the Iran-Iraq war, when Saddam's attempts to extricate himself from his military predicament led to some of the most perilous episodes of the war.

For example, Saddam's desire to punish his enemy economically and starve Iran of oil revenues led him to attack Iran's oil-loading facilities at Kharg Island and sometimes the oil tankers that were docking there. That move partially backfired, as Iran began attacking tankers bound for Kuwait and Saudi Arabia, Iraq's biggest financial backers during the war. The Iraqis counterattacked -- but one of their Exocet missiles hit the USS Stark in May 1987, killing 37 sailors. By July 1987, more than 325 tankers had been attacked.

Saddam also demonstrated during the gulf war that he was willing to use weapons of mass destruction -- ballistic missiles and chemical weapons -- to prevent a military defeat of his forces. He launched the so-called missile war against Iranian cities in 1985 and 1986 in an apparent effort to bring the war to civilians in the capital. And when his army was threatened by waves of Iranian Revolutionary Guards in southern Iraq, Saddam turned to chemical weapons. It is alleged that he continued to use them even in the later stages of the war, against Kurdish dissidents within his own population.

This same approach -- to seize a strategic opportunity and worry later about the consequences -- has been evident in Saddam's week-old invasion of Kuwait, analysts said. The initial move to seize Kuwait was relatively painless. But the next step that Saddam reportedly threatened yesterday -- a possible invasion of Saudi Arabia -- would pose immense difficulties for the Iraqi leader, forcing his army to operate far from home, at the end of long supply lines, in the intense summer heat of the desert.

In taking risks, Saddam appears to have calculated that he could create a new reality in the Persian Gulf by overthrowing Kuwait's ruling family and installing a puppet regime that would give Iraq both the financial and military clout to dominate the region, according to administration officials.

Saddam was able to gauge the U.S. reaction to his military buildup along the border for a week, watching and listening as Washington retreated from stating a commitment to defend Kuwait. U.S. officials now suggest that Saddam reached a judgment that he could move with impunity and present the West with a fait accompli.

"What he does brilliantly is probe for soft spots, then moves swiftly and tactically to a different one," said a U.S. expert on Iraq.

Another administration official with lengthy experience in the region said that Saddam was probably most confident that he could prevent an Arab military response to his move into Kuwait. His calculation of the West's response was less certain, but it did not deter him.

"I think Saddam made a political misjudgment about Western resolve," said the administration official.

"He does take risks, he calculates, but he understands little of the outside world and the scope of measures that can be taken against him," one Saddam watcher explained.

U.S. officials now looking back at his buildup and assault on his weaker neighbor do not believe that Saddam moved with lengthy premeditation. Rather, these officials say, the failure of Kuwait to adhere to its oil quota commitments in the Organization of Petroleum Exporting Countries incited Saddam to think of drastic and permanent solutions.

Saddam positioned forces on the Iraqi border that clearly could overwhelm Kuwait. U.S. intelligence analysts believed that this buildup was initially for intimidation. Saddam made it clear in his meeting July 25 with April Glaspie, the U.S. ambassador to Baghdad, that he had major grievances against Kuwait and that, while the mediation of Saudi Arabia was appreciated, he expected the Kuwaiti crown prince to come to Baghdad and negotiate a settlement.

But during the first phase of talks in Jiddah, Saudi Arabia, the Kuwaitis made it clear they would not knuckle under to Iraqi pressure and would not negotiate in a climate of intimidation.

Some Middle East analaysts in the administration said that Kuwait's refusal to meet Saddam's terms in Jiddah made Saddam's reaction "incalculable," as an intelligence official put it.

Once he made the gamble that he could invade and create a puppet government and withdraw, while holding Arab reaction at bay, Saddam realized that success would make him an economic superpower whose armed forces and oil reserves would allow him to eclipse both Saudi Arabia and Iran in the region.

The United States and its allies responded this week to Saddam's moves with a tough stance he evidently had not expected. But the Iraqi leader has not folded his hand. He has begun preparations for a wider war.

Against a possible attack, Iraq has been drilling millions of its inhabitants for mass evacuation of Baghdad and other cities, where a general military mobilization is underway.

Iraq, barely out of an exhausting eight-year war with Iran, is arming anew. Since the invasion of Kuwait on Thursday, Saddam has ordered the formation of 11 new divisions and reactivation of others dismantled after that war ended.

His government has also announced that 150,000 people in five southern cities have responded to a call for volunteers to join a "popular army" that would serve in Iraq or Kuwait. And in what U.S. and European officials regarded as an especially ominous development, Saddam's troops have taken hundreds of foreigners in Kuwait into custody.

One Arab diplomat in Amman argued that Saddam "has no way out," and "if he does not roll back he will lose his infrastructure as well as the Arab status he so eagerly wants."

The Arab diplomat observed that "regardless of how important Saddam thinks his actions are, what he is doing will not be equal to what will be taken away from him. For the sake of his own continuity, and that of Iraq's, he will have to stop."

Correspondent Nora Boustany in Amman, Jordan, contributed to this story.