Neither the Archbishop of Canterbury nor the Archbishop of York should ever be an anonymous figure. They have a role that extends beyond ecclesiastical bureaucracy and the structure of the next sermon. They also have a duty to discern and then represent the views of the bishops within the Church of England. There is, thus, nothing improper about Rowan Williams, the Archbishop of Canterbury, and David Hope, his counterpart at York, writing to Tony Blair, or other politicians, outlining their shared opinions or those of their colleagues. Indeed, the two men were shrewd to believe that the letter, which is published in The Times today, should have been a private missive to the Prime Minister and not a noisily presented “open letter” as some bishops had wanted.

Much of their document is cogent. On Iraq, the archbishops are right to record recent political progress and to insist that the United States and Britain should constantly seek to show that “the necessary moral authority is demonstrated at every level”. Their assertion that “the apparent breach of international law in relation to the treatment of Iraqi detainees has been deeply damaging” is obviously valid and their sense of a “moral shock” at what occurred inside Abu Ghraib prison is shared by many people. Mr Blair might retort that he did not require censure by the Anglican Church to appreciate either the damage done or to feel a moral shock at what occurred. Bishops, though, have a responsibility to be pious.

They should also, nonetheless, be capable of balance. When this letter moves beyond Iraq to the wider terrain of foreign policy, it shifts from the moral high ground to the ethical minefield. The tone of the comments on the Arab-Israeli dispute, and Britain’s role as an “honest broker”, suggests that a majority of bishops have decided which side they back and are not open to persuasion. The coded attack on supposed “Christian Zionists” in the Bush Administration does not do the authors a service. Besides the paradox of the Anglican Church assailing some public officials in Washington for being too Christian, it is also a cheap shot that does not recognise the sophistication of either the individuals concerned or the wider context of current US politics.

The Archbishop of Canterbury should reflect further on how best to advance his own ideals. He is today a very senior “insider” but appears to be more comfortable with the tactics of the “outsider”, albeit one based in the common room and not the picket line. He is right to sense that he is a serious national figure and, as the leader of a Church represented in many countries, to have an international platform. But he must also recognise that real influence will come from the way in which he exercises his power. He cannot be shy or distant from the debate. He cannot seek out like-minded intellectuals and draw satisfaction just from their company. He might wonder now whether the best means of impressing his fine mind and deep conscience on others would be through a new strategy.

The Anglican Church might be more challenging of its present institutional assumptions on international matters. It is disturbing that there is not a more rigorous debate in the House of Bishops about the most productive means of assisting the poor, the Middle East and the poor in the Middle East.There is instead a form of unreconstructed ideological naivety. Dr Williams, for example, recently offered a lecture that elevated the United Nations to an astonishing secular ecumenical status and came close to implying that the likes of Oxfam should have an official berth on the Security Council. Some might hail all of this as admirable idealism. Others could note, accurately, that it will not help the Archbishop to fulfil his desire to make the world a better place.