The officials said they believe that the last terrorist operation tried by Iraq against the United States was the assassination attempt against the first President Bush during his visit to Kuwait in 1993. That plot was disrupted before it could be carried out. American intelligence officials believe that Mr. Hussein has been reluctant to use terrorism again for fear of being detected.

George J. Tenet, the C.I.A. director, is to testify Wednesday before the Senate Select Committee on Intelligence to review the global threat. During his appearance, his first before Congress since Sept. 11, Mr. Tenet is likely to be asked about a wide range of terrorism issues, including Iraq.

Since Sept. 11, there has been widespread speculation about possible Iraqi links to the attacks on the World Trade Center and the Pentagon, based largely on reports of a meeting in Prague between Mohamed Atta, a leader of the hijacking teams, and an Iraqi intelligence officer. The reports about that meeting have been the subject of intense analysis and debate within the American intelligence community, and some officials even questioned whether the meeting took place.

Now senior American intelligence officials have concluded that the meeting between Mr. Atta and the Iraqi officer, Ahmed Khalil Ibrahim Samir al-Ani, did take place. But they say they do not believe that the meeting provides enough evidence to tie Iraq to the Sept. 11 attacks.

United States intelligence officials say they do not know what was discussed at the meeting. But some experts on Iraq say that even if Iraq were somehow involved in the Sept. 11 attacks, President Hussein would never have entrusted such a sensitive matter to a mid-level officer like Mr. Ani.

American officials say Iraqi intelligence now focuses most of its resources on finding ways to evade trade and economic sanctions that were imposed on Iraq after President Hussein invaded Kuwait in 1990.

Instead, American intelligence officials say their greatest concern is Iraq's continuing development of chemical and biological weapons, covert programs that have resumed since United Nations weapons inspectors left in 1998.

Mr. Hussein apparently feels that such weapons will help his government deter any military attack by the United States and its allies.

A C.I.A. report released last week noted that Iraq is probably continuing low-level nuclear weapons research as well, and that its inability to obtain enough fissile material is the biggest obstacle to becoming a nuclear power.

The major threat to the United States from Iraqi efforts to develop weapons of mass destruction would come instead from Baghdad's parallel efforts to develop long-range missiles, which could be tipped with chemical or biological warheads, the C.I.A. believes.

In his State of the Union address last week, President Bush described Iraq as part of an "axis of evil," which includes Iran and North Korea, that the United States must confront in order to maintain global stability.

Mr. Bush said Iraq "continues to flaunt its hostility toward America and to support terror," but the section of his speech devoted to Iraq focused primarily on Baghdad's efforts to develop weapons of mass destruction. In fact, some American intelligence officials say, the Bush administration does not have enough evidence of Iraqi complicity in anti- American terrorism to justify making Iraq the next target in the war on terrorism.

Some signs have emerged in recent years that President Hussein might consider terrorism as a tool against the United States in the long- running duel over the inspection of suspected chemical and biological weapons sites. In 1998, American and Middle Eastern intelligence agencies discovered that Abu Nidal, the Palestinian who had been one of the most feared terrorists of the 1970's and early 80's, had moved to Baghdad.

Abu Nidal had been ousted from his previous haven in Libya, after Col. Muammar el-Qaddafi decided he wanted to end Libya's ties to terrorists in order to get out from under international sanctions. But Abu Nidal does not appear to have engaged in any anti-American operations since his arrival in Iraq, and he may have ended his terrorism activities, officials said.