In a video message released last week, the Islamic State for the first time made explicit its dependence on a popular uprising in oil-rich Saudi Arabia - home to Islam's two holiest sites in Mecca and Medina - if it is to expand its caliphate beyond Syria and Iraq.
In the process, the jihadist group subtly highlighted how it views the overthrow of the Saudi royal family as a stepping stone towards its ultimate goal of wiping Israel off the map.
"Expel the disbelievers from the Arabian Peninsula," implored a Saudi suicide bomber, in a diatribe recorded last month before he blew himself up.
"The fire begins with a small spark, which will ignite an explosion directed at the House of Saud and their rabbis and priests."
On one level, the reference to "rabbis and priests" was an insult directed at Saudi Arabia's Wahhabi religious establishment.
They rule in partnership with the House of Saud and have been issuing increasingly bold denunciations of the Islamic State in recent weeks on the orders of their terrified princely paymasters.
But on another level it was a reminder to its perhaps millions of sympathisers in the Wahhabi kingdom - who for generations have been told by the very same religious "scholars" that Jews and Christians are the descendants of apes and pigs - of the Christian West's unqualified support for the Saudi royal family, and the latter's long-held policy of maintaining a cold peace with the Jewish state.
The Islamic State's call for jihad in the Arabian Peninsula (like Al-Qaeda, they never call Saudi Arabia by its official name) came days after the Saudis agreed to train and fund a Western-backed Syrian rebel army lumbered with the task of defeating both the jihadists and the Syrian regime.
However, it was also issued in the wake of an extraordinary push by Saudi Arabia to extend its own influence across the Arab world.
Earlier this month, Riyadh opened its biggest ever embassy in Egypt, symbolising how the most populated (and now impoverished) Arab country has been reduced, like Jordan, to reliance on the Saudis and other Gulf Arab monarchies.
In addition to billions of dollars in aid, Egypt's vast Salafist grassroots organisations - who have thrown their weight behind the Egyptian military dictatorship in return for the continued Islamisation of Egyptian society from the bottom up - are on the Saudi payroll.
Saudi Arabia also announced plans to erect a massive security wall sealing its entire 500-mile northern border with Iraq; and it is to build a second causeway linking the country's Shia-majority eastern province to the tiny island of Bahrain. In March 2011, Saudi tanks had rolled over the causeway that already exists to put down a rebellion by Bahrain's Shia masses against their minority Sunni-dominated ruling family.
With the Islamic State bogged down militarily, it hopes that if its call for jihad in Saudi Arabia is heeded, global economic mayhem will ensue along with unimaginable chaos in Egypt and Jordan - the only two Arab countries that have peace treaties with Israel.
● Saudi Arabia has pledged $500 million to help rebuild Gaza, Palestinian Prime Minister Rami Al-Hamdallah has announced, with the full cost of post-war reconstruction expected to be around $4 billion over three years.
Saudi Arabia's commitment comes ahead of a conference in Cairo on October 12 when Palestinian leaders hope other donors, including Turkey, Qatar, the European Union and United States, will also step forward with promises of support.
"Saudi Arabia has initiated donations by pledging $500m," Mr Hamdallah said. He said he hoped further pledges would cover the full cost of reconstruction in time.
John R Bradley's books include 'Inside Egypt' and 'After the Arab Spring'