The long and often frustrating debate over how to respond to the vicious mayhem in the Middle East is over: Up to 40 nations are now either taking part or supporting the United States-led military operation against the Islamic State in Iraq and Syria (ISIS).
Yet the truly critical fight is that being waged inside the Arab world, by governments determined not only to "degrade" ISIS as US President Barack Obama put it, but to destroy it, and prevent the rise of another murderous fundamentalist Muslim organisation in its stead.
It is a battle which will take years, but which has to be won if the Middle East is to escape from its seemingly never-ending cycle of sectarian violence. Yet it is also the sort of battle no Middle Eastern government has ever successfully waged before.
Outside observers often fail to appreciate the grave impact which the rise of ISIS has had on Saudi Arabia, by far the Arab world's richest and most influential state.
Quite a number of ordinary Saudis sympathise with the organisation, and particularly with its claim to be fighting on behalf of Sunni Muslims against Iran and its alleged Shi'ite proxies.
The fact that ISIS espouses the same strict, purist Wahhabist interpretation of Islam which is officially embraced by Saudi Arabia is considered another attraction.
But, as Saudi Arabia's royal family knows only too well, the rise of ISIS is a mortal threat to the Middle East's current political structures.
ISIS' deft media propaganda, complete with gory videos of beheadings, is not only intended to frighten opponents, but also to project an image of radical purity which bypasses the credibility of Arab monarchies.
So, what to many governments in the West looks like just a destructive, mediaeval organisation bent on burning and pillaging comes across to the Saudis and other Arab monarchies as the negation of everything they and their countries stand for.
And, as Mr Alastair Crooke, a retired British spy who currently researches regional politics, argued in a recently published study, ISIS not only threatens to sweep away Arab crowned heads, but may also light the fuse to a far bigger explosion in the Middle East.
Taking on the ISIS
Trying to confront ISIS as an organisation while avoiding too much of a discussion about its ideological roots and its claims to religious purity is the task facing Arab governments. And unsurprisingly, this is easier said than done.
The initial reaction to the rise of ISIS was one of stunned silence. Paradoxically, it was Al-Qaeda which first spoke up against the group, mainly because the older and more established global terrorist outfit felt directly threatened by ISIS, an organisation it dismisses as just an upstart.
It was only late last month that the Grand Mufti of Saudi Arabia, the country's highest cleric, issued a fatwa - a religious edict - in which he declared that "the ideas of extremism, radicalism and terrorism do not belong to Islam in any way, but are the first enemy of Islam and Muslims".
Since then, Arab governments have plucked up courage to go further. Sheikh Jabr al-Saad of the Saudi Ministry of Islamic Affairs announced recently the "close monitoring of sermons delivered at mosques, as well as lectures and religious lessons, to ensure imams are not inciting people to fight abroad".
The kingdom's authorities are also now enforcing a strict ban on the individual issuance of fatwas, which were previously used to justify just about any action. From now on, only officially sanctioned religion committees have such powers.
And Qatar, a Gulf monarchy which hitherto has been reluctant to move against Islamic fundamentalists and often provided them refuge on its soil, has expelled some fundamentalists and issued emergency legislation to regulate charities, the traditional route for channelling cash to extremists.
Speaking with one voice
Arab leaders were also at pains to speak with one voice during the current session of the United Nations General Assembly, by stressing the importance of a coordinated international response to ISIS. "Those who say 'this is not our business' are wrong. The security of every nation will be shaped by the fate of the Middle East," said Jordan's King Abdullah II, speaking for all his neighbours.
The Jordanian monarch also reminded the world that his country is already home to a staggering 1.4 million refugees from Syria alone. That is also a massive but often ignored contribution which Arab states make to stability in their region.
However, the ideological battle between Arab governments and ISIS has only just begun, and is already producing some curious twists.