One year since the Islamic State of Iraq and the Levant (ISIL) took over Mosul and large swaths of territory in both Syria and Iraq, and despite the nine month-old US-led Operation Inherent Resolve to defeat it, ISIL is still standing, and expanding. The group's recent territorial gains in Syria and Iraq are alarming.

Political and military analysts interviewed by Al Jazeera, provide a more sober assessment of ISIL's capacity in both Syria and Iraq behind the sensationalism of the group's propaganda machine and Western punditry's fears of a wholesale ISIL takeover of Iraq and Syria.

Samer Abboud, Assistant Professor of History and International Studies, Arcadia University

ISIL's recent advances in Palmyra have fuelled the recent predictions in Western circles that the collapse of the Syrian regime is near.

A more realistic assessment, however, is that the conflict is mired in a military stalemate in which no armed

Thus far, ISIL has been unable to make military progress in Idlib, Hama, Homs, Aleppo, and Damascus due to its own military weaknesses and the relative strength of regime and rebel forces that control these areas.

group has a definitive advantage over others. The Syrian regime has indeed withered but is not facing a coherent or cohesive military force capable of defeating it militarily, let alone one that can force a negotiated political solution.

ISIL is merely one of many armed groups vying for territorial control of Syria. Yet, they are neither the most militarily powerful armed group nor do they control the major population centres. Thus far, ISIL has been unable to make military progress in Idlib, Hama, Homs, Aleppo, and Damascus due to its own military weaknesses and the relative strength of regime and rebel forces that control these areas.

Though regime forces and their allied militias have retreated in some areas, they remain relatively strong compared to the armed groups and are in control of key transport corridors while continuing to enjoy air supremacy.

Meanwhile, Jabhat al-Nusra-led Jaish al-Fatah [Army of Conquest] has begun to consolidate territorial gains in the northwest. The Kurdish People's Protection Units [YPG] have also proven militarily successful in direct battles with ISIL forces in north and northeastern Syria.

These groups have vied with ISIL over territorial control and it is these battles among and between armed groups that led to the slow fragmentation of the country.

Syria's fragmentation into smaller enclaves reflects the balance of military power between the various armed groups. While ISIL and others appear to control large areas of the country, the main areas in and around the cities remain highly contested with the battle fronts constantly changing and no single group emerging as more powerful than the others.

As such, while ISIL has gained significant territory since the outbreak of the conflict it has also been forced into retreat on multiple occasions.

ISIL's advances must be contextualised within these broader patterns.

A more sober assessment of ISIL's capacity in Syria would suggest that ISIL is hardly winning in Syria, but no armed faction really is.

Salah Nasrawi, Iraqi journalist

When ISIL declared itself a caliphate, with its leader Abu Bakr al-Baghdadi setting himself up as a ruler "by order of God", following the group's advances in June, sympathisers quickly cheered the pronouncement as a heaven-sent victory.

Its spokesman, Abu Mohammed al-Adnani, even boasted that "the legality of all emirates, groups, states and organisations becomes null and void by the expansion of the caliphate's authority and the arrival of its troops to their areas".

To further establish the status of its 'jihadist' state, the group abolished the border between the two Arab countries and began issuing passports to its 'citizens'.

ISIL is probably seen surviving setbacks and probably engineering new advances but its ability to sustain an 'unholy' nation state or even victory in the war remains very much in doubt.

A growing number of zealots from around the world, including Americans and Europeans, flocked to ISIL's territory which runs from northern Syria to the Iraqi province of Diyalah on the border with Iran.

But as followers celebrated, detractors dismissed the declaration of the holy state as nothing more than propaganda. The phenomenon - they believed - was just "a response to the chaos" that had spread in Iraq and Syria. Time, they argued, will prove that such optimism is unrealistic.

Regardless of the likelihood of the global Islamic Caliphate to be accepted on the international and regional arenas, the question remains: Is ISIL insurgency, that has spilled out of local power bases and sanctuaries, sustainable?

It is true that the dramatic fall of Ramadi to ISIL earlier this month made the group control virtually all of Anbar province and pushed it to the edge of Baghdad.

But, the new onslaught may have also exposed how the ISIL insurgency in Iraq has neared its limits.

In order to maintain its gains, ISIL needs to pursue two sets of goals. First, it should win over the Sunni population in areas under its control by striking a delicate balance between its radical religious platform and this population's traditional Arab nationalism. Second, it has to subdue Iraq's Shia population, or at least, force them to leave Sunni areas to ISIL to control.

ISIL has showed no inclination to transform itself into a nationalist Sunni insurgency.

ISIL has ruled vast Sunni areas since last June and there is not much to admire. The group is harsh, narrow-minded and intolerant of dissent. Millions of Sunnis have left their homes and refuse to return. Others are taking arms to fight ISIL in the name of Iraqi nationalism.

On the other hand, the Iraqi Shia, who consider ISIL as an existential threat, do not seem interested in a compromise with ISIL fighters.The Iraqi state, under their control, enjoys legitimacy and support among large numbers of world nations. Their militias on the front line have overwhelming firepower and motivation in the fight against ISIL.

ISIL is probably seen surviving setbacks and probably engineering new advances but its ability to sustain an "unholy" nation state or even victory in the war remains very much in doubt.

Muhammed Abu Rumman, Researcher, Center for Strategic Studies, University of Jordan

A year after its rise in the region, all international efforts to defeat ISIL have failed. Not even the new chapter of "the war on terror" led by the US was able to stop the group's expansion.

Syrian and Iraqi armies, aided by the Iranian revolutionary guards, also failed to deal ISIL a strategic defeat. With its latest victories in Iraq and Syria, ISIL which controls more than 50 percent of Syria has now become larger than many countries in the region such as Jordan and Lebanon.

The Iraqi government is no longer speaking of a decisive battle to remove ISIL out of Mosul. Iraqi officials are more concerned about protecting Baghdad, liberating Ramadi and preventing ISIL from controlling strategic airbases in Anbar province.

As long as there is no international or regional deal on the table that will end the internal conflicts in both Syria and Iraq, conditions on the ground will continue to give ISIL an advantage and manoeuvrability even if it cannot expand its presence beyond the traditional Sunni areas.

In the short term, the internal conflicts in Syria and Iraq are still serving ISIL especially what can be termed as "the Sunni dilemma" whereby the Sunnis feel a real existential threat to their survival and identity as a result of the expansive Iranian influence.

The internal chaos and sectarian conflicts in these two countries constitute an ideal environment for ISIL to thrive and establish its ideological, political, and religious roots.

Moreover, ISIL victories were not shrewd military victories in and of itself, rather it was a natural outcome of the political conflicts in Iraq and Syria.

In reality, this is the core of the problem that faces the US in dealing with ISIL. The US' direct and indirect allies here are Iran, and the Shia militias under its control, as well as a weak alliance of Sunni tribes whom - at one point - were touted at the "lethal weapon" to defeat ISIL.

Given the sectarian environment in the region, Sunnis naturally would choose to side with ISIL. As a result, the group finds a receptive environment in the Sunni regions of Iraq which would make the efforts to defeat it very difficult, if not impossible.

The other factor that helps ISIL in Iraq is President Barack Obama's reluctance to be drawn into yet another war in the Middle East.

Meanwhile, the situation in Syria is equally complicated. The US has no partner on the ground to rely on the same way it has in Iraq. The US choices in Syria are between the Syrian regime and ISIL, or other Islamic groups like Nusra Front, all of which the US considers terrorist organisations.

Given these factors, and as long as there is no international or regional deal on the table that will end the internal conflicts in both Syria and Iraq, conditions on the ground will continue to give ISIL an advantage and manoeuvrability even if it cannot expand its presence beyond the traditional Sunni areas.

That said, however, ISIL has several important weak points that will undermine its existence in the long run and would usher in its sudden collapse in the same fashion it came onto the scene.

The factors that will eradicate ISIL lie in its own ideology which is based on an idealistic and puritan approach to exercise political power.

At the end, there are several factors that are crucial to understanding the mechanism that helped ISIL rise and expand and how it will retreat and fall. While ISIL has developed its own military capabilities, its existence, however, hinges on and is subject to the changing political and regional conditions. This dependency makes its existence temporary and not a permanent one.

Riad Kahwaji, Institute for Near East and Gulf Military Analysis

ISIL made big advances in Syria and Iraq capturing two key cities - Palmyra and Ramadi - in a blitzkrieg. This was not the first time ISIL fighters have achieved such accomplishments.

About a year ago, they pushed their way all through to Mosul within a couple of weeks, and today they occupy nearly half of Syria and one-third of Iraq.

ISIL is not the best armed force on the ground and does not have a quantitative superiority against its adversaries in either Iraq or Syria. However, its combatants are bold, vicious, and audacious and employ tactics based on shock-and-awe with swift blitz.

It takes a unified, courageous and non-sectarian force with adequate firepower [from air or ground] to defeat ISIL, a formula that hardly exists on today's battlefields in Iraq and Syria. So it might be quite a while before we see the end of ISIL.

Acting as precision weapons, ISIL suicide bombers usually open up the assault by hitting key targets that implant fear and breach the adversary's defences, opening corridors for its fighters to move in quickly and outflank their opponents and squeeze them out.

Syrian and Iraqi regular troops have not put up much of a fight in most cases despite the fact that they outnumber and outgun ISIL fighters.

The US Secretary of Defence Ashton Carter commented on the fall of Ramadi by saying that Iraqi troops did not have "the will to fight" and simply withdrew from the city leaving their weapons and vehicles behind.

In other words, Carter was diplomatically saying Iraqi troops deserted their positions and fled the fight.

The same could be said about Syrian troops that withdrew in an organised manner from Palmyra a week after ISIL started its offensive on the historic city and its nearby vital gas fields and phosphate mines.

Moreover, the overdependence of Iraqi and Syrian governments on Iranian-backed Shia militias to fight ISIL has enabled the group to win support and sympathy of many young Sunni men from inside and outside the warzone.

Following the fall of Ramadi, Iraqi Prime Minister Haider al-Abbadi did not call on the Iraqi military to save the city, rather he called on the Popular Mobilisation Forces (PMF), a predominantly Shia militia, to do the job.

US military officials have expressed reservation about the involvement of PMF in fighting in predominantly Sunni areas in Iraq, and called for arming Sunni tribes in order to give them a leading role with the Iraqi Armed Forces in taking on ISIL.

The differences over the strategies and objectives of the war on ISIL between Washington and members of the international and Arab coalition on the one side, and Baghdad and Tehran on the other, has affected the coalition's operations, rendering them ineffective.

Hence, ISIL has been scoring victories in Iraq and Syria because its fighters are yet to face a worthy opponent in a non-sectarian environment as was the case when they came up against the Kurdish fighters in Kobane.

At Kobane, ISIL opponents stood their ground bravely and received considerable air support from the US-led coalition which enabled the Kurds to defeat the group.

So it takes a unified, courageous and non-sectarian force with adequate firepower [from air or ground] to defeat ISIL, a formula that hardly exists on today's battlefields in Iraq and Syria.

So it might be quite a while before we see the end of ISIL.