Sandstorms are unpredictable, but in the case of Barack Obama's rushed trip to Iraq the one that hit Baghdad just as he was landing on Tuesday afternoon was highly unfortunate. US officials were forced to cancel the president's helicopter flight to the Green Zone to meet Iraqi leaders.

Less sensibly, they decided not to allow Obama to travel the roughly eight-mile journey by road. Their decision illustrated just how insecure the Iraqi capital remains in spite of considerable improvements in the last two years. It also meant that Iraq's prime minister and president had to take the risk of going to see the foreign visitor rather than the other way round.

The Obama trip had been designed to draw a contrast with George W Bush's several unannounced visits mainly consisted of talking to US troops. It was also meant to convey an image that Iraq was now a sovereign rather than an occupied and client country. Instead, the truncated four-hour visit's message was that little had changed in US-Iraqi relations.

Obama's initial view of the need to invade Iraq was, of course, different from Bush's. During the election campaign he tossed aside the Bush/Blair mantra that there should be "no artificial timetable" for withdrawing foreign troops. He gave a clear promise that combat troops would leave within 16 months. But Bush was forced to change his line last autumn thanks to growing confidence on the part of Iraq's prime minister, Nouri al Maliki, and mounting pressure from the Iraqi parliament. They persuaded Bush to sign an agreement for troops to leave Iraq's cities by July this year, and to leave Iraq altogether by the end of 2011.

So when Obama took office he inherited a US policy that was not so different from what he had had been advocating. Where there has been change, it tends to go in the opposite direction. While broadly sticking to his promise to pull combat troops out in 16 months (the date of August 2010 he now favours is actually 18 months), he has raised serious doubts about sticking to the 2011 deadline. Now he suggests some US forces may stay after that time, for training or counter-terrorism purposes.

More worryingly, Obama is increasingly adopting a narrative of the US presence that sounds like the Bush version. US troops, Bush always used to say, are in Iraq to defend democracy and provide security until the Iraqis are ready to step up to the plate. Obama now says the same, and expresses concern that as US troops start to leave Iraq violence may resume. It's comforting and paternalistic stuff, designed to paint a picture of neutral peacekeepers nobly holding the ring until the natives grow up or come to their senses.

Undoubtedly, Obama has a difficult role to perform as commander in chief. It's hardly to be expected that he would tell US troops to their face at the optimistically named Baghdad airport headquarters Camp Victory that they have been risking their lives for nothing. But he could have hinted that while most soldiers did their duty with professionalism and discipline, the political leaders who sent them there were mistaken and ill-informed.

By the same token, it makes domestic political sense for Obama to say he wants to conduct the US withdrawal "in a responsible fashion". But he should not fall for the Bush-style argument that "I have a responsibility to make sure that, as we bring troops out, we do so in a careful enough way that we don't see a complete collapse into violence" - the phrase he used to students in Istanbul shortly before flying to Baghdad.

Why doesn't Obama consult Iraqi opinion? The latest poll, by the BBC and ABC in February, shows that nothing has changed in the longstanding majority view that the occupation forces (British as much as the Americans) have not been a bastion of security. They have been the problem more than the solution. Sixty-nine per cent said they had "done a bad job". Forty-six per cent think they should leave Iraq before the end of 2011, while 35% said the timetable is right. Less than 20% want them to stay longer. One reason is that Iraqis by a 53% majority view the US as still running the country. Another is that 59% already think Iraqi forces are capable of providing sufficient security.

It is true that sectarian tensions and violence between Sunnis and Shias still exist in Iraq (a phenomenon that was insignificant during Saddam's era and the previous two or three decades). It is also the case that clashes between the Sunni Awakening Councils and the Shia-dominated army and police have recently broken out, largely because of a hasty government policy of disbanding the councils, many of whom earlier led the anti-US resistance.

But the Iraqi public, and the main parties in parliament, express confidence that violence can be contained. On Tuesday Obama told US troops rather haughtily that it was "time for Iraqis to take responsibility for their country". He should listen rather than lecture. Iraqis have been trying to give the US that very message for quite some time.