It is not clear in the latest media reports on the new Iraq crisis whether the Obama administration is considering air strikes designed only to take out ISIS targets or if the existence of ISIS in Syria and Iraq is to act as the pretext to try and take out President Assad's military assets in Syria.
From the beginning of 2014, Assad's forces have rolled back the Sunni insurgent forces from the area around the capital Damascus, partly because ISIS started only this year to engage militarily with both the Free Syria Army and Kurdish separatists in northern Syria
Previously, in 2013, ISIS was a staunch jihadist ally of the Free Syria Army in attacking the forces of the Democratic Union Party (PYD) of Kurdistan. As a consequence of rivalries with the Free Syria Army and its desire to align with forces within Iraq opposed to Baghdad, ISIS broke away from the FSA.
Whereas the FSA and its Western and Gulf allies backers have accused Assad of backing ISIS as a means to draw their forces into a diversionary war, Kurdish militias in northern Iraq may have colluded with ISIS in order to weaken the Maliki government in Baghdad because of disputes over the export of oil.
The danger is that Washington is going to use accusations that Assad has backed ISIS, as opposed to simply having not attacked them through realising they could fight the the FSA, to launch the air stikes it was prepared to launch in August 2013 after the Syrian military's alleged gas attack on Ghouta.
Of course, ISIS has been regarded by Western intelligence reports leaked to the media as an offshoot of Al Qaida that Assad may have abetted. Certainly, there have been defections as the competition for control over oil supplies has ensured the survival of the most brutal and pathologically violent groups.
However, even if Assad has played a murky double game with the Sunni jihadists and foreign fighters forming ISIS, the vast majority of the funding and provision of the weapons that has created this situation of increasing 'radicalisation' is from Saudi Arabia and Qatar, both of which are competing to get the most effective jihadist group fighting for their interests.
What Washington and London fear is that Assad has outplayed the West by turning its use of jihadi assets in Syria as a means of thwarting the plan, mostly backed by Qatar, to use Al Qaida affiliated groups such as the Al Nusra Front and Ahrar al-Sham to overthrow him.
Qatar has resisted forthrightly any attempt to change that foreign policy, one that has led to quarrels with Saudi Arabia which had previously supported Al Nusra but has started to fear jihadi influence spreading back home and preferred to bankroll more 'moderate' jihadi groups such as Jaysh al-Islam.
Saudi Arabia has attempted to persuade Washington to lift restrictions on supplying this new 'improved' jihadi group with anti-aircraft and anti-tank missiles to give it the edge over Al Qaida affiliated groups ( still backed by Qatar ) and, of course, the Muslim Brotherhood.
Washington could regard the deep incursion into Iraq by ISIS as too good an opportunity to miss in using it as a pretext to roll back Assad in Syria and to make saving Maliki's Shia government in Iraq through effective use of air power, conditional on breaking its arms deals with Iran and trying to reach out to Iraqi sunni Muslims.
By so doing, Washington could decisively scupper any potential realisation of the proposed 'Islamic pipeline' between Iran, Iraq and Syria that would allow Tehran to export gas to the Eastern Mediterranean and thwart the preferred Qatar-Turkey pipeline that is proposed from the South Pars fieldb both Gulf powers share.
Apart from the benefits of hemming in Iran as part of a broader attempt to encircle and destroy the regime in Tehran through sanctions, Washington would be able to decisively set back Russia's plans to control the gas supply to Europe from the Eastern Mediterranean.