One Iraqi opposition group is headed by a smooth-talking exile mistrusted by much of the US government. A second has close ties to Iran’s radical Shiites.

The two main Kurdish factions still do not get along. And one of the few former generals viewed as credible is under investigation for war crimes.

The opposition groups courted by US officials are split along ethnic and political lines. They have histories of infighting and betrayal. Several accuse the United States of past betrayal.

None is guaranteed to be effective against Iraq President Saddam Hussein, who has defeated numerous revolts and coup attempts. Yet the groups could prove key to any US effort to overthrow Saddam — or perhaps even more importantly, essential to governing Iraq once Saddam was gone.

As talk of war increases, the Bush administration has invited half a dozen Iraqi opposition groups to Washington for talks, possibly this month.

A look at the most important, from the US perspective:

— The Iraqi National Congress, headed by longtime exile Ahmed Chalabi, is a London-based umbrella group of opposition figures that has received millions of dollars in US aid. But many US diplomats and intelligence officials regard the group as inept or untrustworthy with little support among other Iraqis.

The INC’s main US support now appears to be in Congress and among some top civilians at the Pentagon. The group is receiving little US aid at the moment.

The group was created in 1992 to bring together disparate groups, including Shi’ites and Kurds. Operatives worked inside northern Iraq until Saddam’s army ousted them in 1996. Some view America’s failure to protect the group then as a betrayal.

— The Iraqi National Accord, based in London, also is made up of Iraqi exiles, including former military men from the dominant Sunni sect inside Iraq. The group claims it has closer links to military leaders still inside Iraq. The group has had links with some US intelligence officials.

In 1996, the INA was involved in a coup attempt against Saddam that did not succeed, according to both its supporters and detractors. Saddam’s security services apparently learned of the coup and prevented it.

— The Patriotic Union of Kurdistan and the Kurdistan Democratic Party, main Kurdish groups that control a large portion of northern Iraq, with protection from US and British jets patrolling a no-fly zone. They have created quasi-democratic governments and relatively vibrant economies there in recent years.

The factions are bitterly divided, and there are other Kurdish splinter groups. The PUK is led by Jalal Talabani, the KDP by Masoud Barzani.

Together, the Kurds are estimated to have as many as 80,000 armed men organised into militias, making them one of the few credible Iraqi fighting forces against Saddam.

The Kurds are leery of any US attack against Saddam unless they receive guarantees they will continue to have autonomy in the north. Neighboring Turkey — a key US ally — opposes any independent state for the Kurds.

— The Supreme Council for the Islamic Revolution in Iraq, a Shi’ite group based in Iran’s capital, Tehran, and in London, claims to have 10,000 armed men inside Iraq. It opposes any U.S.-backed effort to overthrow Saddam, saying any effort should be led by Iraqis or the international community.

Shi’ites make up about 60 percent of Iraq’s population, even though the smaller Sunnis have dominated Iraq politically.

— Gen. Nizar al-Khazraji, a former high-ranking general in Saddam’s army during the Iran-Iraq war in the 1980s who defected in 1995 and now lives in Denmark. The highest-ranking officer to escape Saddam’s government, he is believed to still have links within Iraq’s military and has expressed interest in helping the opposition.

But al-Khazraji is under investigation by Danish officials for possible war crimes. He was the Iraqi army’s chief of staff during Saddam’s poison gas attacks on Kurds in 1988, and at least one Kurdish group calls him responsible. The two main Kurdish factions have defended him; he says another Iraqi official was responsible. -- AP