A lot of debates going on about the breakaway between Jabhat al Nusrah and al Qaeda, whether the group should indeed distance itself from their cental affiliate or not. West seems up to press Nusra to do so, yet the jihadist group doesn't seem willing to down their head to the West. The breakaway could bring consequenses and and in long terms small "advantages".
Strategically speaking the breakaway of Nusra would bring international legitimacy and a sort kind of immunity to the group, taking them out of the terrorist list and joining the ceasefire list, and even getting invitation to the Peace Talks.
It is clear the will of US and other countries in this breakaway, since al Nusra is one of the biggest group fighting in Syria at the moment, focusing in local jihad and capable of fighting and ovethrowning the assadist regime. US first strategy of backing more moderate fighters (FSA linked fighters) already failed and part of this failury was thanks to Nusra who manage to seize the group. So in US mind, nothing more logical than supporting the group that was strong enough to capture their own trained soldiers.
On the other hand, islamically speaking, breaking away with AQ could change part of Jabhat al Nusra's aqeedah and manhaj, turning them into a more moderate group, engaging in irjah (murji'ah action), causing the loss of their jihadi legitimacy.
AQ is a strong and influencial organization in the jihadist world and part of this is due to the fact that alongside Taliban, AQ is the oldest jihadist group in the jihad of nowadays. They have far more knowledge and experience in jihad (war and islam) they already have a solid aqeedah and a good amount of scholars. All this gives legitimacy to the small groups overseas giving bayah to them, most of these groups, including al Nusra, are relatively new groups that need a strong base to keep them together and give them a direction.
The other possibility though is that this breakaway could affect the group in the opposite way, turning them into a more radical faction like Jund al Aqsa, or Turkistan Islamic Party, groups that dont give ba'yah (pleadge alligancy) to AQ nor IS but still bear a even more radical ideology than JN. The same happened with the Islamic State when they broke their bayah with al Qaeda creating an independent group that ended up being more radical than their old school model.
It should be bear in mind that breaking away with al Qaeda doesnt necessary means breaking away with their Salafi ideology. It is hard to predict what path JN would choose without AQ but in both cases, this breakaway could bring benefit but also disunit between JN fighters and split their ranks.
—–
Ahrar al Sham is one of the few jihadist groups in history to take aid from non muslims or secular countries, this happens for the simple fact that accordiangly to the understanding of great part of Islamic scholars, this act goes against the Islamic Law.
As already mentioned by AS itself, even though both groups are Salafists/Jihadists groups, they dont share the same projects. Due to circumstances that weakened Ahrar in the past, in 2014 the group started to show the first signs of moderation.
Although they share a lot of similarities, different than Ahrar al Sham, Jabhat al Nusra has a far more radical Aqeedah that doesnt approve this kind of support, and they are not up to be signing any agreement, like this of the breakaway, for the sake of pleasing the West only.
—–
Al Qaeda has long planned to declare an Islamic State. With the situation in Syria after the Arab Spring, and all the chaotic enviroment turned Syria into the perfect incubator for the new generation of jihadi, AQ saw an opportunity in that. JN has this goal of establishing an Islamic State in Syria. As there can only have one legit Islamic State at the time, if these two groups were divided, AQ wouldn't be able to declare a State if Nusra did and vice versa.
As Zawahiri said in his last audio message: We have repeated over and over than the Muslims of Sham – and at the heart of them the brave Mujahidin – if they formed their Muslim state and chose their Imam, then whoever they decide to choose is their choice. This shows there is no need for JN to leave AQ in order to establish their Islamic State and instead of opposing to this, AQ would actually join them(give bayah).
As mentioned by Zawahiri: We, by the grace of Allah, are not striving for authority, rather we are striving for the rule of the Sharia. We do not wish to rule over the Muslims, rather, we want to be ruled as Muslims by Islam. Jihad is about unification of the muslim people and groups and not about spliting ranks and falling apart, together they are more powerful than against each other.
—–
US seem to be up to try supporting radical groups again, despite the bad experience they had in Afghanistan with the Taliban. But they must bear in mind their past experience, Ahrar al Sham's aqeedah doesnt represent the pattern of all jihadist groups, not all of them are willing to take aid from a western country nor down their heads to western policies and agenda.
Seems like Nusra is more interested in fighting against the Regime with all their ways than getting out of the West's terrorist list. Perhaps because they don't care about titles, perhaps because they don't care about the western projects.
Although some people agree with this breakaway, it is not a simple issue to solve, and would bring alot of consequences to the group. Despite all the pressure JN has being suffering regarding this matter, It is something that we wont probably see any time soon.