The US military is now seeing over 800 soldiers killed and wounded every month, bringing the total number of its dead soldiers to 2,942 and wounded to 22,032 since the invasion of Iraq three years and nine months ago. Going by the current casualty rate, total US casualties will exceed 25,000 some time this month, according to figures released by the US department of defence.

US president George W Bush is considering sending between 20,000 and 35,000 extra soldiers as reinforcements for the 140,000 US troops already in Iraq to try regain control of Baghdad and insurgent Sunni provinces such as Anbar.

At the same time Bush is pushing Iraqi prime minister Nouri al-Maliki to reform his government by severing his links with the nationalist Iraqi cleric Muqtada al-Sadr and allying himself with supposedly moderate political leaders who have close links to the US. A conference on national reconciliation held in Baghdad this weekend has been denounced by Sunni leaders as a PR ploy.

Both the political and military initiatives being considered are fraught with danger. Even 10 extra US combat brigades, the number envisaged by hawkish Republican senator John McCain during a recent visit to Iraq, would be unlikely to lead to military victory. The population of Iraq is 27 million and the reinforcements would only be able to expand the limited islands of US control. An American military offensive to try to control Baghdad during the summer petered out without any gains on the ground.

A sign of greater US belligerence may be the appointment of lieutenant general Raymond Odierno as the new US commander in Iraq.

During a previous stint leading the 4th infantry division in 2003 and 2004 stationed north of Baghdad, Odierno won a reputation for Vietnam-style search-and-destroy operations in which many local farmers were killed and innocent onlookers imprisoned. The heavy losses among Iraqi civilians provoked a powerful reaction in favour of the Sunni guerrillas and has been cited by some US officers as an example of how not to conduct counterinsurgency operations.

The additional US troops may also be used for an offensive against the Mehdi Army militia of Muqtada al-Sadr which is in control of much of Baghdad and is a growing force in the rest of Iraq. The US blames its Shia militiamen for the sectarian bloodbath in Iraq this year, though they are not alone in this.

Their main sin in the eyes of Washington is that they are deemed antiAmerican. Abdul-Aziz al-Hakim, the leader of the Shia party the Supreme Council for Islamic Revolution in Iraq, was favourably received by Bush in Washington last week though his party's militia, the Badr Organisation, also runs death squads, private prisons and torture chambers.

Previous attempts by the US military to quash Muqtada al-Sadr's movement in 2004 led to heavy fighting and strengthened his prestige among Shia. The report on Iraq by James Baker earlier this month estimated that the Mehdi Army has at least 60,000 men under arms. It is now much better organised, trained and led than two years ago when its militiamen were unpaid and used their own weapons.

The US has been trying to force al-Maliki either to abandon his connection to Muqtada al-Sadr or step aside. The danger of this course is that al-Sadr is highly regarded by most of the Shia who make up 60% of the population. His father, Mohammed Sadiq al-Sadr, murdered with two of his sons by Saddam Hussein's gunmen in 1999, was the most effective Arab opponent of the old regime. Al-Sadr's blend of religion, nationalism and social works is highly popular among the Shia. He controls 30 out of 275 seats in parliament and five ministries.

While decrying sectarian and ethnic politics in Iraq the US is increasingly enmeshed in them. Ever since the first Gulf War in 1991 the US has sought to evade the fact that the natural consequence of overthrowing Saddam Hussein was that the Shia religious parties would triumph at the polls.

Washington has been trying to put together an alternative coalition of Kurds, Sunni parties and some of the Shia parties such as SCIRI. This is an attractive option for Sunni and secular leaders who did poorly in the parliamentary elections last year but any new coalition formed under this plan will be highly dependent on the US.