Once installed, Obama called, like every US president, for peace between the two suffering peoples of the Holy Land, and again, like every predecessor, for Palestinians to recognise Israel and for Israel to stop its settlements in the territories it seized in 1967. Within a week of the President's speech in Cairo pledging opposition to further settlements, the governing Netanyahu coalition was extending Jewish properties in East Jerusalem with impunity. However, war-zones further east have the first call on imperial attention. In 2002, on his way up the political ladder as a low-profile state senator in Illinois, Obama opposed the attack on Iraq; it was politically inexpensive to do so. By the time he was elected President, his first act was to maintain Bush's Defence Secretary, Robert Gates, long-time CIA functionary and veteran of the Iran-Contra affair, in the Pentagon. A cruder and more demonstrative signal of political continuity could hardly have been conceived. Before his election, Obama promised a withdrawal of all US ''combat'' troops from Iraq within 16 months of his taking office, that is, by May 2010 - with a safety clause that the pledge could be ''refined'' in the light of events. It promptly was. There persists the uneasy thought that the Iraqi resistance, capable of inflicting such damage on the US military machine only yesterday, might just be biding its time after its heavy losses and the defection of an important segment, and could still visit havoc on the collaborators tomorrow, should the US pull out altogether. To ensure against any such danger, Washington has put down markers in the modern equivalents - vastly larger and more hideous - of the Crusader fortresses of old. As for Iran, schemes for a grand reconciliation between the two states had to be set aside. The calculation was upset by political polarisation in Iran itself. For Obama, the opportunity for ideological posturing was too great to resist. In a peerless display of sanctimony, he lamented with moist-eyed grief the death of a demonstrator killed in Tehran on the same day his drones wiped out 60 villagers, most of them women and children, in Pakistan.

The Democratic administration has now reverted to the line of its predecessor, attempting to corral Russia and China - European acquiescence can be taken for granted - into an economic blockade of Iran, in the hope of so strangling the country that the Supreme Leader will either be overthrown or obliged to come to terms. From Palestine through Iraq to Iran, Obama has acted as just another steward of the US empire, pursuing the same aims as his predecessors, with the same means but with a more emollient rhetoric. In Afghanistan, he has gone further, widening the front of imperial aggression with a major escalation of violence, both technological and territorial. When he took office, Afghanistan had already been occupied by US and satellite forces for more than seven years. During his election campaign, Obama - determined to outdo Bush in prosecuting a ''just war'' - pledged more troops and fire-power to crush the Afghan resistance, and more ground intrusions and drone attacks in Pakistan to burn out support for it across the border. This is one promise he has kept. In what The New York Times delicately described as a ''statistic that the White House has not advertised'', it has informed its readers that ''since Mr Obama came to office, the Central Intelligence Agency has mounted more Predator drone strikes into Pakistan than during Mr Bush's eight years in office''. Desperate to claim victory in a self-chosen ''just war'', Obama has dispatched a still larger expeditionary force, expanding the war to a neighbouring country where the enemy is suspected of finding succour. It was announced that Pakistan and Afghanistan would henceforward be treated as an integrated war-zone: ''Afpak''.

If a textbook illustration were needed of the continuity of American foreign policy across administrations, and the futility of so many softheaded attempts to treat the Bush-Cheney years as exceptional rather than essentially conventional, Obama's conduct has provided it. From one end of the Middle East to the other, the only significant material change he has brought is a further escalation of the War on Terror - or ''Evil'', as he prefers to call it - with Yemen now being seen as the next target. Still, it would be a mistake to think that nothing has changed. No administration is exactly like any other, and each president leaves a stamp on his own. Substantively, vanishingly little of US imperial dominion has altered under Obama. But propagandistically, there has been a significant upgrade. In Cairo, at West Point, at Oslo, the world has been treated to one uplifting homily after another, to describe America's glowing mission in the world, and modest avowal of awe and sense of responsibility in carrying it forward. Cant still goes a long way to satisfy those who yearn for it. Tariq Ali is a London-based historian, writer and political campaigner who is in Australia to deliver the 2010 Edward Said Memorial Lecture at Adelaide University. He will be speaking in Melbourne tonight at the Melbourne City Conference Centre.