BBC News, Tehran
Some hardliners in Iran are calling for the cancellation of talks planned between the US and Iran over Iraq, arguing the negotiations would only legitimise the foreign occupation of Iraq.
Ayatollah Khamenei says the US should leave Iraq alone
Some news reports say the negotiations will begin this weekend in Baghdad, although there is no confirmation of this.
If the talks are held and publicly announced, they would be the first open, direct discussions between the US and Iran since Iran's Islamic Revolution of 1979.
Despite the opposition from hardliners, some Iranian policymakers and analysts say the dialogue could benefit Tehran.
"A large section of Iran's economic and business activities, politics, and the security of its western border depends on security and a stable government in Iraq," said Reza Talainik, a member of the parliament's National Security and Foreign Policy Commission.
"And if the United States cannot create stability and security in Iraq, America's performance would seriously be questioned by the people."
Iran's Supreme Leader, Ayatollah Ali Khamenei, said last month that Iran would agree to the talks in order to tell the US to leave Iraq alone and let the Iraqi people govern themselves.
Iran's interests in Iraq
Tehran has repeatedly called on foreign troops to leave Iraq as a prerequisite for stability there and in the entire region.
But Tehran also seems glad to maintain the status quo.
Some observers say Iran wants to see a balance between an Iraq unstable enough to keep Washington occupied but stable enough to prevent the disintegration of Iraq or chaos spilling over Iraq's borders.
The US has accused Iran of inciting instability in Iraq by aiding insurgents. Tehran denies the charge.
Some analysts also say if the dispute over Iran's nuclear programme intensifies, and the US leads an attack on Iran, foreign troops in Iraq would serve as a good target for Iran.
"I think in both cases, Iran would be a winner," said Hossein Hafezian, an Iranian expert in Middle East studies. "If US troops leave tomorrow, Iran can say it was a quagmire for the US, who failed.
"If they remain there, Iran can have leverage and say the US is vulnerable to our actions.
An officer in Iran's elite Revolutionary Guards confirmed his country would be able to use the foothold it has gained in surrounding countries to strike back at US troops.
"The US has a lot of military bases around Iran," said the officer, who declined to be identified.
"We can certainly hit them, either by infiltration or through military means. We have the ability to resist - even in the US itself."
Over the past week, Iran has been performing war games in the Gulf, daily announcing tests of missiles and torpedoes.
Iran's foreign minister has said these weapons are mainly for defence.
And parliament member Mr Talainik said Iran had no "need or desire" to attack foreign forces stationed in Iraq.
"Iran has never used and will never use the inside of Iraqi soil for confronting its enemies," he said.
But he added: "In the situation of a threat to Iran's security by whichever country, Iran will have the possibility of retaliation in kind as it has forecast."
When asked to elaborate on the type of retaliation, he only replied: "It depends on the conditions."
Shia Muslim Iran could offer to try using its ties with Iraq's rival Shia parties to reach agreement on the formation of a new government.
And Iran could help strengthen security in Iraq by tightening its controls over the Iran-Iraq border.
But it is questionable how much the talks could help create stability in Iraq.
Iran and the US may simply use their meeting to trade allegations with each other, and some Iraqi Shia groups may be reluctant to be seen as bowing to Iranian pressures.
It is also unclear how much Iran could help dampen Sunni-led rebellions in Iraq - a point that Hamidreza Taraghi, a senior aide to Iran's president, acknowledges.
"Some Sunni groups and even [one Iraqi Shia leader] Moqtada Sadr, who don't trust America, believe these negotiations will be useless and that the only solution is the exit of the occupiers from Iraq," he said.
"This is also our belief, but we're ready for negotiations in order to show our good intentions about solving the problems of Iraq."
What Iran could gain
Iran is also concerned about violence in its south-western province of Khuzestan, home to many of Iran's ethnic minority Arabs.
Iranian officials have blamed a recent wave of bombs there on exiled separatist groups and British forces in southern Iraq. London denies the charge.
Iran may also like to take up issues such as the continuing presence of members of Iran's main armed exiled opposition group, the Mujaheddin-e Khalq, in northern Iraq.
And Iran could use the meeting with the US to try to reach a deal on its disputed nuclear programme.
But whatever the outcome of the talks, Iran could gain recognition of its regional importance just by taking part in them.