The Islamic countries, both dominated by the mainstream Sunni sect, have long had a particularly close relationship and these events heightened speculation Riyadh is trying to strike a secret deal with Islamabad to acquire nuclear weapons to counter Iran.
Abdallah's surprise July 19 appointment of Prince Bandar bin Sultan, the kingdom's ambassador in Washington in 1983-2005 and a veteran of its usually clandestine security policy, as his new intelligence chief may be part of murky mosaic linking Saudi Arabia and Pakistan.
Bandar played a key role in the clandestine arming of by the United States and Saudi Arabia, via Pakistan's intelligence service, of the Afghan mujahedin during the 1969-79 Soviet invasion.
Bandar's appointment as the head of Saudi Arabia's General Intelligence Presidency, its foreign intelligence service, was one of several critical security related command changes made in recent days.
These took place as the kingdom, the world's largest oil exporter, faces a swarm of regional challenges, the most prominent of which is nuclear wannabe Iran.
As the confrontation between the United States and Iran over Tehran nuclear program builds up in the Persian Gulf, Riyadh is increasingly looking eastward to longtime ally Pakistan, the only nuclear Muslim power, for support.
"As Iran becomes more dangerous and the United States becomes more reluctant to engage in military missions overseas, Pakistan and Saudi Arabia may find that renewed military and nuclear cooperation is the best way to secure their interests," observed Christopher Clary and Mara E. Karlin, former U.S. Defense Department policy advisers on South Asia and the Middle East.
Writing in The American Interest, they noted: "As the United States re-examines its military posture toward South Asia and the Middle East in the context of its withdrawals from Iraq and Afghanistan, it must explicitly consider the possibility of a Saudi-Pakistan nuclear bargain.
"The failure to take such a scenario seriously could promote its occurrence."
U.S. plans to effectively withdraw militarily from Afghanistan in mid-2013, as it did in Iraq last December, have intensified Pakistani concerns about Islamic jihadists.
This mirrors Saudi suspicions that after Iraq and Afghanistan it can no longer rely on the United States for protection.
The Saudis too face a jihadist threat, particularly from al-Qaida in the Arabian Peninsula that's based in neighboring Yemen.
It's long been believed that the Saudis bankrolled Pakistan's nuclear program, in the 1970s and '80s and now wants some reciprocity in the shape of readymade nuclear weapons, paid for by massive financial aid for Islamabad.
Israel's Debkafile Web site, considered close to Israeli intelligence and which sometimes posts reports considered to be disinformation, claimed in December 2010 that Pakistan has set aside two nuclear weapons for Saudi Arabia.
These, it said, are believed to be stored at Pakistan's nuclear air base at Kamra in the north.
At least two giant Saudi transport planes sporting civilian colors and no insignia are parked permanently at Kamra with aircrews on standby," Debka reported.
"They will fly the nuclear weapons home upon receipt of a double-coded signal from King Abdallah and the director of General Intelligence," who now happens to be Prince Bandar, reported to be close to the monarch.
The Saudis have of late portrayed their high-tension rivalry with the Iranians as a new, menacing chapter in the 1,300-year-old struggle between Sunni and Shiite Islam.
"The stakes are enormous," says Bruce Reidel, a former counter-terrorism specialist with the CIA wrote in the German newsmagazine Der Spiegel.
"Pakistan has the fastest growing nuclear arsenal in the world. It will soon surpass the United Kingdom as the fifth-largest nuclear arsenal.
"It's the sixth-largest country in the world in terms of population. It will soon surpass Indonesia as the country with the largest Muslim population."
A leading Saudi royal, Prince Turki al-Faisal, who headed the GIP in 1977-2001, warned U.S. and British military chiefs meeting outside London June 8, 2011, that Tehran's acquisition of nuclear arms "would compel Saudi Arabia ... to pursue policies which could lead to untold and possibly dramatic consequences."