FACTBOX: Iraq's tricky relationship with Iran

(Reuters) - Iraq's Prime Minister Nuri al-Maliki is visiting Tehran for talks with Iran's leaders for the second time in 10 months.

Following is a factbox on Iraq's relationship with Iran:

HOW INFLUENTIAL IS IRAN IN IRAQ?

Iraqi officials acknowledge Iran has a lot of influence in the country, partly through its ties with Shi'ite politicians and parties that were based in Iran for years during the rule of Saddam Hussein, a Sunni Arab.

Iran has an embassy in Baghdad, unlike most Arab states that have only low-level ties.

Iran showed its influence by helping to end fighting in the southern city of Basra in late March between Shi'ite cleric Moqtada al-Sadr's Mehdi Army militia and Iraqi security forces.

Iran also played a key role in a deal struck by Iraqi Shi'ite factions to end seven weeks of fighting in Sadr's Baghdad stronghold of Sadr City, a senior Shi'ite Iraqi legislator said in May.

Ali al-Adeeb, a member of the ruling Shi'ite alliance who is close to Maliki, said an Iraqi delegation that went to Tehran almost two weeks earlier asked for Iranian help because of Tehran's influence over Sadr's movement.

Sadr is believed to be living in the Iranian city of Qom, where he is taking advanced Islamic studies.

Iraq is also looking for Iranian help with supplying electricity, which is in short supply in Iraq. Electricity Minister Karim Waheed said on Friday he would accompany Maliki to Iran and press the country to resume work on a power line between Abadan in southern Iran to the Iraqi city of Basra.

WHAT ABOUT THE ACCUSATIONS AGAINST IRAN?

Washington accuses Iran of funding, training and arming Shi'ite militias, particularly "rogue" elements of Sadr's Mehdi Army called "special groups". Iran denies the charges.

The U.S. military says it has detainees in custody who say the Iranian-backed Lebanese group Hezbollah is providing training near Tehran for Iraqi militants. The camps are run by the Qods Force, a wing of Iran's Revolutionary Guards.

U.S. officials have stepped up their rhetoric against Iran since Maliki cracked down on militias in Basra in March. That offensive led to the discovery of what the U.S. military calls "very, very significant" amounts of Iranian weaponry.

WHAT IS THE IRAQI GOVERNMENT'S VIEW?

Some Iraqi officials seem genuinely perplexed about Iran's intentions. One said recently that Iran needed to make up its mind. "It's either Maliki and this present day leadership of Iraq or these militias. It cannot have them both," he said.

The government said last month Maliki had ordered the formation of a committee to compile evidence of Iranian "interference" in Iraq that would then be presented to Tehran.

A U.S. military official has said there had been a "sea change" in Baghdad's view of Iranian activity in Iraq since the discovery of the new weapons, especially after Iran assured Maliki last year that it would help stabilize Iraq.

Iraq has also insisted it does not want to get caught in a proxy war between Tehran and Washington, arch foes who are also embroiled in a dispute over Iran's nuclear ambitions.

WHAT IS THE PURPOSE OF MALIKI'S TRIP?

Maliki wants to foster closer economic ties. His electricity minister may sign agreements to buy refined fuel for Iraqi power plants.

Government spokesman Ali al-Dabbagh said Maliki would also raise allegations of Iranian interference in Iraq's affairs. He would address Iranian concerns about a new military pact being negotiated between Iraq and the United States, reminding Tehran that Iraq was free to sign agreements with whomever it wanted.

WHAT IS THE IRAQ-IRAN HISTORY?

Iran and Iraq fought an eight-year war in the 1980s in which hundreds of thousands were killed. Ties have improved since Saddam was ousted in the U.S.-led invasion and a Shi'ite-led government came to power in Baghdad.

Iraq is an Arab nation while Iran's roots are Persian. Both countries have majority Shi'ite populations.

Iranian officials have called for the withdrawal of U.S. and other foreign troops who they blame for destabilizing Iraq. Iran regularly voices support for Maliki's government.

(Baghdad newsroom)