He issued his warning on 20 January, the very day that Barack Obama was inaugurated as US president.

Obama has made crystal clear his determination to relaunch the Middle East peace drive, despatching his new peace envoy, George Mitchell, to the region almost as soon as he had taken office.

But King Abdullah’s remarks, made to the Arab League summit in Kuwait, highlight the pressure piling up on Riyadh. The new US administration will need Saudi Arabia as a strong ally in its efforts to revive the fading hopes of a land-for-peace deal in Israel and the Occupied Territories.

Just in case the full seriousness of Saudi concern about the Arab peace initiative had been missed, Prince Turki al-Faisal, the kingdom’s former ambassador to London and Washington, weighed in three days later with an article in the UK’s Financial Times newspaper. Where King Abdullah had been clear but diplomatic, Prince Turki’s assessment was blunt.

“Unless the new US administration takes forceful steps to prevent any further suffering and slaughter of Palestinians, the peace process, the US-Saudi relationship and the stability of the region are at risk - America is not an innocent in this calamity,” he said. “Not only has the Bush administration left a sickening legacy in the region, but it has also, through an arrogant attitude about the butchery in Gaza, contributed to the slaughter of innocents.”

Tougher stance

Prince Turki went on to report that Iran’s President Mahmoud Ahmadinejad had written to King Abdullah urging the Muslim world to take a tougher line, and warned that it was becoming ever harder for Saudi Arabia to resist calls for a Muslim jihad against Israel.

Moreover, his brother, Foreign Minister Prince Saud al-Faisal, has told the UN Security Council that if there is no just settlement, “we will turn our backs on you”.

It is hard to overstate the significance of such public statements. Rarely in recent decades has the kingdom’s leadership expressed its fears and anger about the crisis in the Middle East in such graphic terms. Since launching the Arab Peace Initiative in 2002, when he was crown prince and head of day-to-day government, King Abdullah has consistently promoted an agenda of dialogue and moderation.

Through refraining from speaking directly about the Palestinians’ deteriorating humanitarian situation, King Abdullah has been careful to maintain his position as a reliable, if sometimes critical, friend of the US, one who has shown ready understanding of the domestic political complications that face a US president who is trying to nudge Israel towards compromise in negotiation.

However, it is now clear that not only is Saudi Arabia angered by Israel’s resorting to massive military retaliation in January for Hamas missile attacks launched from Gaza, but it is also increasingly fearful that the “moderate” Arab stance is no longer tenable.

Like other governments in the region, Riyadh is acutely aware of the wide domestic public anger over attacks on Palestinians, which has increased following the bloody images of civilian casualties that appeared almost continuously on Arab satellite TV screens throughout January.

Saudi Arabia was the decisive player in getting the Arab world to sign up to the principle of a two-state solution for Israel/Palestine. As a result, Riyadh has become a key staging post on the international diplomatic itinerary.

After the awkwardness provoked by former president George W Bush’s aggressive pushing of a democratisation agenda in the Middle East, Obama’s pragmatism - more focused on regional policy goals than the bullish promotion of a particular reform model - will certainly be welcomed by the kingdom.

If progress can be made by Obama, Saudi Arabia will be a crucial player. If Israel can be induced to re-engage in serious peace negotiations, with a view to settlement, in the foreseeable future, it is Saudi money and political clout that will play an essential role in persuading Hamas or Syria to participate.

Meanwhile, Saudi Arabia is also emerging as a critical player in the group of major emerging economies engaged in global efforts to stabilise the world economy. King Abdullah was at the November 2008 summit of the G20 leading economies in Washington, and his government will once again be a key voice when G20 leaders gather in London in April.

His message to the November gathering was not adventurous, reiterating the routine case for energy market dialogue and stressing Saudi willingness to help poor countries cope with the effect of the crisis.

“We will continue to fulfil our role in ensuring the stability of the oil market and assisting developing countries, in co-operation with the international community, to ensure the recovery and growth of the global economy,” he told fellow heads of state.

“Saudi Arabia is aware of the pivotal and critical role it plays in the global economy and in ensuring the stability of the international oil market. Our country’s oil policy is based on balanced principles, taking into consideration the interests of both the producing and consuming countries.”

Such words sound unexceptional but were exactly what fellow government leaders wanted to hear. When it comes to the oil market, Saudi Arabia’s importance lies in its cental role in maintaining stability of supply and helping to limit the wild price volatility of the past year.

Of course, Saudi Arabia has plenty of money, albeit contingent on the oil price. But traditional money-backed diplomacy, brokering localised crises, is not always successful.

Changing mood

After all, as Gregory Gause, a Saudi expert at the University of Vermont, points out, Saudi Arabia’s system of government - its de facto absolute monarchy - limits its capacity to offer other countries an attractive political model. The kingdom’s attempts to sponsor diplomatic settlements, such as Syria/Lebanon, have not always lasted in the long term.

Saudi Arabia’s greater international strength may lie not in adventurous global politicking but in its conservatism, and the fact that Riyadh does not rapidly shift positions. It can act as a store of diplomatic stability in uncertain times.

This is what makes the kingdom such a key potential partner for the Obama administration.

The Saudis maintain a central line around which the majority of the region’s governments tend to gather, despite their localised individual initiatives. Iran’s President Ahmadinejad may express Muslim anger over the Israeli assaults on Gaza or Lebanon in terms that more graphically catch the public mood.

However, his government’s capacity for influence will always be undermined by the concerns over Tehran’s true agenda held by many Arab countries.

Saudi Arabia’s clout and assumption of regional readership may sometimes stir resentment in smaller or poorer countries. But they still tend to follow the kingdom’s broad lead.

This is what makes the recent warnings from the Saudi leadership so significant. King Abdullah and his advisers detect signs of a changing mood across the region, a resentment and frustration that goes far beyond the usual talk of “the Arab street”.

Although the kingdom does not enjoy the naturally close relationship with Obama’s new team that it had with the more conservative administrations of former US presidents George Bush and George W Bush, there is still scope for the Saudis to develop a natural partnership with the US, says Ali al-Ahmed, director of the Institute for Gulf Affairs, a Washington-based think tank and campaign group.

In particular, the Saudis hope that the US will give the support that could help counter Iran’s ambitions in the region, and the way that Tehran has used a vocal line on the Palestine issue to attract regional support.

This is one of the factors driving Saudi pressure over Palestine, says Al-Ahmed. “The reason they now want to get involved as much as possible is because the Iranians are coming to the region through that door,” he explains.

Riyadh does not yet seem quite sure how much support it will get from President Obama. King Abdullah was not among the initial batch of Middle East leaders called by the new president just after coming to office.

“They are testing the waters with the Obama administration,” says Al-Ahmed.

But perhaps not too much should be read into this. Obama’s first calls were only to the direct protagonists in the Middle East crisis: Israel and its closest neighbours. Even key Nato partners, such as the UK and France, had to wait.

Obama may not offer Saudi Arabia the warmly effusive words that the Bush dynasty was always ready to utter. But he may yet provide the kingdom with a more stable and consistent policy partnership than was ever on offer from the last US administration.