Gerd Nonneman: Delicate relationship where national interests and morality often conflict

The relationship between Britain and Saudi Arabia – or, more accurately, the ruling Al Saud family – dates back just over a century to when the founder of modern Saudi Arabia, Abdulaziz Al Saud, aiming to obtain counterweight to Ottoman attempts at control, looked to Britain as the regional hegemon.

Today, it is King Abdullah Bin-Abd-al-Aziz Al Saud who rules. Some 30,000 Britons live in the kingdom, with another 100,000 thought to go on the Hajj every year.

London's and Riyadh's policies towards each other have been driven primarily by pragmatic considerations of political and economic advantage. Certainly religious and political issues of conviction, matters of pride and intercultural communication have, on occasion, come to the fore – such as King Faisal's decision to impose an oil boycott, the furore in 1980 over the documentary Death Of A Princess, or the often ill-informed British media commentary about the nature of Saudi politics. On their own, such issues tend not to reorient policy very significantly or for very long. Yet they do have the potential to complicate relations even when neither government wants them to.

In some years, arms and related sales to Saudi Arabia have been worth half of Britain's total visible trade with the kingdom. The huge Al-Yamamah contracts with BAE Systems have been estimated to have supported some 30,000 British jobs. Yet similar deals also inadvertently highlight some of the more problematic aspects of the relationship.

Persistent allegations of corruption over the original 1980s contract against both BAE and members of the royal family fed into the often simplistic negative image-making in the British media. The halting of the Serious Fraud Office's investigation into the case in 2007, after the intervention of the Prime Minster, highlighted both the UK's economic interest and Saudi-British intelligence cooperation on the containment of violent jihadism. The episode also showed some pitfalls of the relationship in terms of different perceptions and political-legal structures.

Currently, there are both "positive" and "negative" factors affecting emerging shifts in the relationship. On one side, Saudi Arabia is increasingly important for the UK and the global economy, given trends in energy markets. Britain remains the second-largest investment partner in the Saudi market. The heightened common concern for the containment of radical jihadism in Saudi Arabia, the UK, and elsewhere, adds further cement, alongside the long-established British view of Riyadh as a moderating force in Middle Eastern politics. And the UK remains a useful part of Saudi Arabia's strategy of avoiding over-dependence on the US alone.

On the other side, Saudi Arabia's economic needs and its capacities are changing – in ways that dovetail neatly both with what a rising Asia needs and what it can offer. It also fits the Saudi preference for geostrategic and geo-economic diversification.

There will always be areas of friction and disagreement, as some rest on diverging interests, and some on diverging values. Yet especially at governmental level, much of this will be surmounted when viewed "in the round" and over the longer term.

After all, the key mutual interests remain too valuable to be overlooked – whether in economics, security in the Middle East, or the containment of violent radicalism. But equally perhaps, a dose of realism is required in accepting that, from the Saudi point of view, Britain's importance in its global strategic and economic matrix has probably entered a phase of relative, if gentle, decline.

The writer is Professor of Middle East Politics at Exeter University and a fellow of the Royal Institute of International Affairs