There can be no absolute argument one way or another. The whole point of diplomacy is that it is an expression of compromise, so the fact that Saudi Arabia might be an exceptionally intolerant place is not a reason in itself to refuse a state visit. Some commentators have noted that Gordon Brown refuses to meet Robert Mugabe at the EU-Africa summit next month, but is happy to play host to King Abdullah. Those are the compromises on which diplomacy is built.
A second reason why it is hard to be definitive is that it is hard to know what a state visit actually means. Diplomacy, in its purest sense, is words and not action. We can invite the Saudi king here, treat him well, and still not change our policies towards his country if we wish. Alternatively, we could have refused to invite him and still deal with Saudi Arabia on exceptionally generous terms. Diplomatic relations are a veil behind which the real business is done: all we see is the motorcade down The Mall; we do not get to look behind the veil.
By contrast, compare the EU’s dealings with Serbia. It has negotiated a Stabilisation and Association Agreement, but refuses to sign it until Serbia cooperates fully with the International Crime Tribunal for the former Yugoslavia, most notably by arresting and handing over for trial Ratko Mladic. That is action and not words. As long as Serbia fails to comply, it will remain outside the European process. No such pressure is brought to bear on Saudi Arabia, but then there is probably no such leverage either.
Saudi Arabia is a key player in the many of the conflicts and crises around the Middle East – the war in Iraq, the tension with Iran, the continuing problem with Israel and the Palestinians – and, given that we need its help (or at least not its active opposition) to achieve our objectives on those questions, there is not much we can do. Politeness is probably a wise course of action, in all the circumstances.
In that light, I think that Vincent Cable, acting leader of the Liberal Democrats, should have been willing to attend the state banquet held as part of the visit. He has complained about the Saudi human rights record, but as I have said, this is only a state visit and not anything more important. It is interesting that he was invited to attend: state visits are not just contact with the government of the day but with our whole political system.
That is not to say that he has to support government policies, but it is to say that friendly relations are better than antagonistic ones, and the rules of gracious behaviour still apply. (For the same reason, I think it was wrong for the president of Columbia University to harangue President Ahmedinejad before he spoke in New York in September.) We don’t have to like them but we do have to deal with them. It is only diplomacy, after all.