According to experts, say it could be around for years to come.
Although the group has suffered setbacks in the months since it was proclaimed. A US-led coalition is carrying out airstrikes against ISIS throughout its territory and this week it lost the key Syrian border town of Tal Abyad to Kurdish forces.
On the other hand, the group has gained victories elsewhere, including the seizure of Syria's ancient city of Palmyra.
Experts have also claimed that say ISIS and its "caliphate" have the means to last for years.
"The group operates as an insurgency and might shrink in one region and expand in another, but it'll stay with us for the foreseeable future," said Hassan Hassan, associate fellow at the Chatham House think tank's Middle East and North Africa programme.
"I see it existing and active for at least a decade."
"The very idea of the caliphate and Bagdadi will surely remain for many of the movement's members and supporters around the world," said Charles Lister, a vising fellow at the Brookings Doha Center think thank.
Various factors including significant financial resources, superior firepower, and ability to play on the legitimate grievances of local populations in Syria and Iraq have played crucial role in its advancement.
"It remains the richest terrorist group in the world," with weekly revenues of about $2 million (1.7 million euros), said Patrick Johnston, a political scientist at the Rand Corporation think tank.
However, attack on oil infrastructure and fall in the price of crude oil have some adverse impact on its funds, but it has secured money from different ways like extortion, taxation, and the sale of looted goods from areas they have captured
More importantly, the group's operating costs are relatively low: it has a steady supply of recruits, particularly foreign fighters, and its vast armoury is stocked largely from the spoils of battles against armies and other rebel groups.
Fighters have access to a range of small arms and light weapons, as well as artillery, anti-tank guns and a "seemingly unending supply of pick-up trucks and captured armoured vehicles and, in Syria, tanks," according to Lister.
He said the group seeks to "ensure a near-constant series of tactical-level victories are won, thereby resulting in the capture of additional weapons supplies.
"ISIS also buys arms from the black market, making it "one of the most equipped groups in Syria and Iraq," said Hassan, author of a book on the group.
Lack of reliable ground forces and relatively poor intelligence has compelled US-led coalition fighting against ISIS.
ISIS eyes on the areas having local government and weak security. And it quickly implements governance in captured territory.
"They use a carrot-and-stick approach with local populations, terrorising with brutal public executions but also offering relative stability and public services including healthcare and education," Johnston said.
The lack of alternatives has been key to IS's success in Syria and Iraq, where a number of Sunni Muslims apparently feel excluded from the ruling class.
In Syria, Sunni Muslims have led the uprising against President Bashar al-Assad, who hails from the Alawite offshoot of Shia Islam.
In Iraq, they frequently accuse the Shia-led government of discrimination.
Those dynamics mean a purely military approach to the "caliphate problem" will fall short.
"Ultimately the only genuine solution to ISIS is to solve the underlying issues of societal division and political failure that ISIS has sought to exacerbate and exploit to its advantage."
(The story was earlier published in AFP)