Saudi Arabia is expanding its military arsenal to counter what it sees as Iran's growing influence in a region convulsed by violence.
Analysts and diplomats say that Israel's bombardment of Lebanon has added to alarm in Saudi Arabia, which is predominantly Sunni, at Shia Iranian policies in the Middle East.
"There is now an understanding that Iran has to be countered," a Saudi adviser said. "There is going to be a huge strategic spending on defence, based on a new defence doctrine."
Over the past year Saudi officials have spoken publicly against Iranian influence in Iraq and the possibility of Iran acquiring nuclear weapons. Saudi Arabia has also blamed the Shia Hizbullah for provoking the Israeli blitz which has ravaged the infrastructure of Lebanon and killed more than 350 people.
"Iran has been a lot more aggressive [ over the last year] . . . it has made the Saudis sit up in a way they haven't for a good 10 years," said a western diplomat in Riyadh. "Who in the long term is their main strategic threat? They see it as Iran."
Saudi Arabia wields considerable global political clout, partly because it is the world's top oil exporter, and over the past week it has spent billions of dollars on military equipment.
Washington said on Thursday that it had approved the sale of 24 UH-60L Black Hawk helicopters, radios, armoured vehicles and other military equipment worth more than $6 billion. France and Saudi Arabia also signed a defence co-operation agreement on Friday, with a French government source saying a deal was close on helicopters and tanker aircraft. Riyadh is also set to buy up to 72 Eurofighter Typhoon jets in a deal with Britain which could cost over $10 billion.
According to independent defence intelligence provider Jane's Information Group, tight public finances held up military expansion plans in the 1990s. But a spectacular rise in world oil prices has since turned Saudi fortunes around.
"The relatively small Royal Saudi Land Forces are thinly spread to cope with potential threats on a number of fronts. Saudi Arabia has far smaller ground forces than those of Iran," Jane's said in a report last month, estimating the army at 70,000 men and the elite National Guard at 77,000.
Saudi Arabia relied on US military protection from the time of the 1990/91 Gulf War until 2003, when the troops left because American backing was seen as no longer politically acceptable.
Iran has emerged as a major Saudi concern since President Mahmoud Ahmadinejad took office last year. "Iran is invading the Arab world and burning everything in its path," columnist Mshari Al-Zaydi wrote in the Saudi daily Asharq al-Awsat this week. "With the Arabs standing idly by, Iran seeks to impose its control over the region."