The US still faces a long struggle in Iraq and recent security gains are not irreversible, the outgoing commander of the country's troops in Iraq warned today.
General David Petraeus delivered his sombre assessment in an interview with the BBC as he prepared to hand over his command to General Ray Odierno, his former number two in Iraq.
Petraeus has been credited with pulling Iraq back from the brink during his 18 months in charge of US operations. Sectarian violence has dropped sharply and US casualties are down. US troops are now suffering more casualties in Afghanistan than in Iraq.
Petraeus adopted a cautious tone in his interview with BBC's Newsnight, saying he did not know that he would ever use the word "victory".
"This is not the sort of struggle where you take a hill, plant the flag and go home to a victory parade," he said. "It's not war with a simple slogan."
As he prepares to assume charge of the US central command, which has responsibility for an area stretching from the Middle East to Pakistan, Petraeus said there were "many storm clouds on the horizon which could develop into real problems".
US military commanders in Iraq are worried that violence could flare up during provincial elections, which were originally scheduled for this month but were postponed after the Iraqi parliament failed to agree on a new electoral law.
Iraq's parliament must pass the law by the end of this month if elections are to take place this year. The law has been held up partly by disagreements among ethnic Kurds and other minorities about the unresolved status of the oil-rich city of Kirkuk.
There is concern over a renewed Sunni-Shia schism as the Shia-dominated government moves to assert control over the Sunni volunteers who have successfully battled al-Qaida.
These 100,000 or so Sunni fighters have been paid by the US, but Nouri al-Maliki's government has said it would take over payment and find them jobs. There is renewed tension between Sunnis and Shias following the recent arrest of several Sunni leaders.
The US president, George Bush, announced the withdrawal of 8,000 troops from Iraq this week, a pace in the reduction in combat troops that was both slower and smaller than anticipated.
US commanders see little alternative to keeping a big troop presence – about 140,000 soldiers - in Iraq for now because the situation remains fragile.
Baghdad, however, has made it clear in current talks on a security pact that it would like all US combat forces to leave by 2011.