The Council of
Foreign Relations (CFR) made the assumption that al-Qaeda cells
(sleeping or active) already penetrated in 100 countries.



I submit an extract of two articles you can read through the respective link.
The first written in March 2016 is posted on washingtoninstitute while the second is written by Charles Lister and published these days.
The washingtoninstitute make geopolitical analysis while Charles Lister is a journalist supporter of the moderate Syrian rebels.
Below are two plied with the respective link so you can get an idea that the risk of creating an Islamic state terror does not come only by ISIS as well as al-Qaeda, which currently controls the majority of the Syrian anti-government factions

www.washingtoninstitute.org/policy-analysis/view/how-to-prev

The Institute for the Study of the War has identified more than sixty rebel groups in the western Aleppo area, with a total of some 60,000-90,000 fighters. Jabhat al-Nusra is not the largest of these factions: its 10,000 fighters are only half that of the group Ahrar al-Sham, for example. Yet Ahrar and many other militias are now allied with JN, and while those who fight for secular and "moderate" Islamist groups may account for as many as a third of the area's rebel forces, they are mainly found in small, locally recruited units with a few hundred fighters or less.
The most important "moderate" unit is Division 13, a member of the coalition Fatah Aleppo. Supported by the United States and Turkey, the group claims to have 2,000 fighters and has been battling the Syrian army in Aleppo and the Kurdish People's Defense Units (YPG) in the Azaz corridor. Since the Russian intervention began last year, many small groups not affiliated with JN have put aside their Islamist banners and other trappings, joining coalitions with nationalist names such as Jaish al-Nasr (the Army of Victory) and al-Jabah al-Shamiya (the Levant Front). They have done so not only to receive U.S. military aid, but also to resist JN's hegemonic pressures.

foreignpolicy.com/2016/05/04/al-qaeda-is-about-to-establish-

Al Qaeda has big ambitions in Syria. For the past three years, an unprecedented number of veteran figures belonging to the group have arrived in the country, in what can only be described as the covert revitalization of al Qaeda’s central leadership on Europe’s doorstep. Now the jihadi group’s Syrian affiliate, the Nusra Front — having spent nearly five years slowly building deep roots in the country — is laying the groundwork for al Qaeda’s first sovereign state.
The Islamic State and al Qaeda use different tactics in Syria, but their ultimate objective there is the same: the creation of an Islamic emirate. Whereas the Islamic State has imposed unilateral control over populations and rapidly proclaimed independence, al Qaeda’s Syrian affiliate has moved much more deliberately, seeking to build influence in the areas they hope to rule. This is a long-game strategy that the terrorist group began adopting in the late 2000s, first in Yemen, in 2011, and then in Mali, in 2012.

Having a broader vision of the phenomenon you can clearly understand the size of the danger that the creation of a terrorist nation create a domino effect on all neighboring ones.
Here is the game world security and not that of Syria which is only one pawn on the chessboard.
Seek dialogue with these people does not create security, but puts off the moment of capitulation.
Uncontrolled immigration accelerates the spread of cancer by creating metastases then difficult to eradicate.
Enjoy the reading

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