Since at least 2004, a significant goal of the group has been the foundation of a Sunni Islamic state. Specifically, ISIL has sought to establish itself as a caliphate, an Islamic state led by a group of religious authorities under a supreme leader—the caliph—who is believed to be the successor to Prophet Muhammad.
In June 2014, ISIL published a document in which it claimed to have traced the lineage of its leader al-Baghdadi back to Muhammad, and upon proclaiming a new caliphate on 29 June, the group appointed al-Baghdadi as its caliph. As caliph, he demands the allegiance of all devout Muslims worldwide, according to Islamic jurisprudence (fiqh).
ISIL has detailed its goals in its Dabiq magazine, saying it will continue to seize land and take over the entire Earth until its:
Blessed flag...covers all eastern and western extents of the Earth, filling the world with the truth and justice of Islam and putting an end to the falsehood and tyranny of jahiliyyah [state of ignorance], even if American and its coalition despise such.
— 5th edition of Dabiq, the Islamic State’s English-language magazine.
According to German journalist Jürgen Todenhöfer, who spent ten days embedded with ISIL in Mosul, the view that he kept hearing was that ISIL wants to “conquer the world” and all who do not believe in the group’s interpretation of the Koran will be killed. Todenhöfer was struck by the ISIL fighters' belief that “all religions who agree with democracy have to die”, and by their "incredible enthusiasm"—including enthusiasm for killing "hundreds of millions" of people.
A map circulated around the internet purporting to show historical areas of former Muslim states in Europe, Asia, and Africa, that ISIL planned to expand to, was created by outside supporters and had no official connection to ISIL.
When the caliphate was proclaimed, ISIL stated: "The legality of all emirates, groups, states and organisations becomes null by the expansion of the khilafah's [caliphate's] authority and arrival of its troops to their areas." This was a rejection of the political divisions in Southwestern Asia that were established by European countries during World War I in the Sykes–Picot Agreement.
Strategy
According to Jason Burke, a journalist writing on Jihadi Salafism, ISIL goal is to "terrorize, mobilize, polarize".
Terrorize to intimidate civilian populations and force governments of the target enemy "to make rash decisions that they otherwise would not choose". Mobilize its supporters by motivating them with, for example, spectacular deadly attacks on enemy soil such as the November 2015 Paris attacks. Polarize by driving Muslim populations—particularly in the West—away from their governments, thus increasing the appeal of the ISIS caliphate among them. "Eliminate neutral parties through either absorption or elimination".
A 2004 work published online entitled Management of Savagery (Idarat at Tawahoush), described by several media outlets as influential on ISIL, and intended to provide a strategy to create a new Islamic caliphate, recommended a strategy of attack outside its territory in which fighters would:
Diversify and widen the vexation strikes against the Crusader-Zionist enemy in every place in the Islamic world, and even outside of it if possible, so as to disperse the efforts of the alliance of the enemy and thus drain it to the greatest extent possible.
— Scott Atran, Paris: The War ISIS Wants
Terror attacks on soft targets like resorts will require expenditures for security that will weaken the "crusaders".
If a tourist resort that the Crusaders patronize…is hit, all of the tourist resorts in all of the states of the world will have to be secured by the work of additional forces, which are double the ordinary amount, and a huge increase in spending, while inspiring disaffected youth who are naturally rebellious and energetic. The terror will motivate crowds drawn from the masses to fly to the regions which we manage, particularly the youth… [For] the youth of the nation are closer to the innate nature [of humans] on account of the rebelliousness within them — Scott Atran, Paris: The War ISIS Wants and will also draw the "Crusaders" into a quagmire of military conflict:
Work to expose the weakness of America’s centralized power by pushing it to abandon the media psychological war and war by proxy until it fights directly.
— Scott Atran, Paris: The War ISIS Wants
One observer has described ISIL's publicizing of its mass executions and killing of civilians as part of "a conscious plan designed to instill among believers a sense of meaning that is sacred and sublime, while scaring the hell out of fence-sitters and enemies."
Another describes it purpose as to "break" psychologically those under its control "so as to ensure their absolute allegiance through fear and intimidation", while generating "outright hate and vengeance" by its enemies.
Documents found after the death of Samir Abd Muhammad al-Khlifawi, a former colonel in the intelligence service of Saddam Hussein's air defense force who has been called "the strategic head" of ISIL, detail planning for the ISIL takeover of northern Syria which made possible "the group's later advances into Iraq". Al-Khlifawi called for the infiltration of areas to be conquered with spies who would find out "as much as possible about the target towns: Who lived there, who was in charge, which families were religious, which Islamic school of religious jurisprudence they belonged to, how many mosques there were, who the imam was, how many wives and children he had and how old they were." Following this surveillance and espionage would come murder and kidnapping -- "the elimination of every person who might have been a potential leader or opponent". In Raqqa, after rebel forces drove out the Assad regime and ISIL infiltrated the town, "first dozens and then hundreds of people disappeared."
There is no known involvement in any form of conflict resolution. In Fall 2015, the first moves at all inclusive talks about talks were made by Irish mediator Jonathan Galway-Jackson to the anti-war leader of the opposition in Britain Jeremy Corbyn to construct a form of "track 2 diplomatic talks" at INCORE in Ireland involving all parties including Daesh political representative/s.