Saudi Arabia's King Abdullah issued a dire warning at a reception for foreign ambassadors last week. "I ask you to transmit this message to your leaders: fight terrorism with force, reason and speed," he said, claiming that the jihadis will launch attacks throughout Europe and the US within months if left unchecked in Syria and Iraq.
Just days earlier, the Islamic State had called for its Saudi-based cells to launch attacks in the first week of October to precipitate an Islamist uprising against the House of Saud.
Since neither London nor Washington needed the Saudi king's wake-up call, what he was really saying was that Saudi Arabia is next on the jihadis' hit list. There was a note of desperation in his accompanying plea that Washington "do something" before it is too late.
Israeli Prime Minister Benjamin Netanyahu simultaneously said in a televised speech that Israel had agreed to a permanent truce in Gaza to keep focused on the threat from regional militants. "We are in a situation where the Islamic State is at the gates of Jordan, al-Qaeda is in the Golan and Hizbollah is at the border with Lebanon," he said.
Of course, Mr Netanyahu and King Abdullah could not mention an unspeakable reality: that the fate of these two very different but key Western allies hangs on whether the Islamic State is crushed in Syria or expands its caliphate into the Arabian Peninsula.
Not that either country got much reassurance from Washington.
US President Barack Obama announced only that his administration had "no strategy yet" for dealing with the Islamic State, while subtly chiding "Sunni states" - ie Saudi Arabia and Qatar - for having used the jihadist groups as "proxies" in the Syrian civil war.
Observers were perplexed by the "no strategy" admission; but the explanation was in the president's "proxy war" allusion.
After all, the secular Syrian regime and its ally, Russia, have been arguing since the outset that the conflict is a foreign-funded jihad than a civil war - a war that, lest we forget, the CIA and other Western intelligence outfits were deeply involved in, via Turkey, in its first two years.
The dilemma is that while the West and the Gulf Arab states have lost control of the jihadists, there is no easy, face-saving strategy to bring President Bashar Al-Assad back into the fold.
For if Washington accepts Damascus's recent offer of a military alliance, it would mean fighting alongside Hizbollah and Iran's Republican Guard while admitting that Moscow was right all along - all of which is inconceivable.
On the other hand, if the US bombs the Islamic State inside Syria and - as it has a habit of doing in its bumbling military campaigns - fails to take it out, it will embolden the jihadists while rallying their supporters elsewhere.
The resulting anti-US backlash would make an uprising in Saudi Arabia even more likely.
Amid the chaos, Iran would make a move on the oil fields in Saudi Arabia's eastern province, where the majority population is Shia, and on the Sunni-dominated (but Shia-majority) Saudi client state of Bahrain.
Jordan's monarchy would fall to the Muslim Brotherhood within days of the House of Saud's overthrow, meaning Saudi Arabia and Israel's arch rivals, Qatar and Iran, would emerge triumphant.
Small wonder, then, that Mr Obama has decided for the time being that doing nothing is the best option, presumably in the hope that the Syrian regime and the Islamic State bog each other down while the Iraqi government gets its act together and Saudi Arabia remains stable.
But that is one hell of a gamble - leaving the Jewish state's fate to a risky bet on the longevity of the Saudi royals, whose wealth and hateful Wahhabi ideology is responsible for having fomented this Suez-like debacle.