"Considering the kingdom's vital strategic position in the international community, as well as its place at the centre of the global war on terrorism, such deficiencies are particularly dangerous," CSIS said in its report. "In general, the weakness of the GIP is one of the critical national security problems facing Saudi Arabia".
The CSIS report was released just days before Saudi Arabia hosts a counter-terror conference which it says aims to pool international experience in tackling terrorism world-wide. It also followed the resignation of GIP chief Prince Nawaf bin Abdul-Aziz who replaced Prince Turki al-Faisal shortly before the September 11 2001 attacks, carried out mainly by Saudi hijackers. Nawaf suffered a brain haemorrhage in 2002 but remained in post until his resignation last week.
No replacement for Nawaf has been announced.
"The GIP has become markedly less effective since the departure of Prince Turki," the CSIS report said. "Most of the sophisticated networks that had been established over many years have deteriorated and hence the GIP's role in the global war on terrorism has been marginal at best".
It said the head of the GIP, which has an estimated $500 million a year budget, is theoretically responsible for intelligence gathering and analysis and co-ordinating intelligence tasks of all Saudi intelligence agencies.
But in practice "at the operational level there now is no real Saudi intelligence community". Efforts are being made to improve co-ordination and sharing of intelligence, it added. Saudi Arabia is battling a 21-month campaign of suicide bombings and killing by militants loyal to al Qaeda leader Osama bin Laden, who aim to expel non-Muslims from the world's biggest oil exporter and topple the ruling pro-US Saud family.
In December, militants detonated two car bombs near the Interior Ministry and an emergency forces building in the capital. They also stormed the US consulate in the Red Sea city of Jeddah.
But Saudi security forces have killed or arrested many of the most wanted militants and the government says it has broken the back of their violent campaign.