As Tony Blair doggedly toured Israel and the Palestinian Authority yesterday, it was said that his efforts had been undermined by events in Washington. Informed sources there suggested that George W. Bush was poised to reject the key recommendations of the Iraq Study Group, increasing rather than decreasing US troop numbers in Iraq and declining to make the revival of the Israeli-Palestinian peace process the centrepiece of his broader regional strategy. Neither Mr Blair, Ehud Olmert, his Israeli counterpart, nor Mahmoud Abbas, the Palestinian President, seemed to be especially perturbed by these reports and their talks were conducted as business as usual. This was, perhaps, because they were less concerned about the details of US policy towards Iraq or the Israel and the Palestinians than ensuring that America remained vigorously involved in their region.

The attitude of much of the outside world towards the United States could be summoned up in five words: “Do something but not that.” The sole superpower is both expected to have a policy for every square inch of Earth and condemned as the source of all evil for anything that goes wrong. The White House is supposed to convince Iran and North Korea not to pursue nuclear weapons programmes without issuing any threats against those states, eliminate the al-Qaeda menace through intellectual arguments alone and ensure that various African countries do not become failed states at the very same time. The United States is condemned for having “messed up” in the Middle East, yet at the same time is attacked for having not followed up this allegedly disastrous approach by intensive diplomatic engagement in the same theatre.

It is time for two crucial points about the US and the wider world to be acknowledged.

The first is that the world needs the United States to be fully engaged in international affairs. If that is to occur, a degree of realism is essential. History teaches us that the power of any potentially dominant actor is either exercised fully or not at all. Calls for the US to be “multilateral” are legitimate in the sense that it is always wise to collect allies but are often code for the notion that it should devote its forces to any and every cause. It is allegedly all-powerful and fundamentally flawed. It should be neutral, but take the right side in every conflict that emerges.

The United States is being asked not only to be the world’s policeman but also its pyschologist and social worker. It is a wholly implausible and inconsistent set of demands.

The second relates to the Middle East as it exists at the moment. Increasing the number of US troops in Baghdad does not discount the option of drawing down the military force in Iraq by 2008: it may be the only means to achieve that end. Nor is Mr Bush betraying his closest ally by expressing scepticism about whether the road to peace throughout the Middle East runs via an Israeli-Palestinian settlement. Such a political accord would be a welcome outcome. But even if it transpired, such a resolution would have little impact on the Shia-Sunni struggle in Baghdad, or dissuade Iran from its nuclear plans or oblige al-Qaeda to abandon terrorism. It would be a wonderful start yet far from the end of the road.

Changes in the composition in Congress are likely to make the United States more isolationist and protectionist next year. Is that what the world really wants of Washington? Those with contempt for American foreign policy should be careful what they wish for this Christmas.