Hordes of black clad fighters overrunning historic Middle Eastern cities, brutal Hollywood-style executions and thousands of recruits flocking from across the globe has made ISIS a priority enemy as its shift from contagion to pandemic gathers momentum.The wide ranging informal coalition, which is united in the fight against ISIS, grows larger and more committed by the day, with the significant addition of Turkey last month being seen by many as a "game-changer".RELATED: The deep roots of Turkey's war on ISISISIS is described by world leaders as evil incarnate, barbaric and inhumane, a virus rather than a human creation that needs to be destroyed.So how evil is ISIS? Is it an evolution in both the ideology and application of violence, or rather, does it represent the "perfect enemy", which allows a variety of political actors to pursue their own agendas under the guise of fighting them?Whether it's the Turks looking to address domestic issues concerning their Kurdish population, the Syrian regime looking to divide those opposed to it, or European countries implementing wide-scale domestic security policies, many are fighting ISIS in different ways for substantially different reasons.Irrational evilHowever, the umbrella of "irrational evil" that places ISIS on the same plane as the Orcs from Lords of the Rings, allows actors to pursue policies without the same degree of scrutiny and critical interrogation.Firstly, observers of ISIS often fall into the trap of being historic.The fighters did not suddenly emerge unheralded from underground, but rather were the product of the state collapse and civil strife that followed the 2003 Iraq War and the 2011 Syrian conflict.Writing in the Guardian, Natalie Nougayrede argued that "it is precisely because civilians are not being protected that ISIS has been able to grow. ISIS has been able to cast itself as the sole protector of Sunni civilians as they continue to be massacred by the barrel bombs and air power of the Syrian regime". There is much misinformation being circulated about the scale and origins of sectarianism in the modern Middle East, but there can be little doubt of how ISIS chooses to use it as a source of legitimacy.By demonising ISIS, you remove any sense of needing to understand that legitimacy, and instead, focus entirely on whatever response you choose to pursue.A Pentagon press briefing last year laid out in no uncertain terms that ISIS fighters "are an imminent threat to every interest we have", while world leaders have engaged in an arms race to see who can describe ISIS in the harshest terms.Network of deathLast year, US President Barack Obama described ISIS as a "network of death" and warned that "there can be no reasoning, no negotiation with this brand of evil".British Prime Minister David Cameron, meanwhile, has described the fight against ISIS as the "challenge of a generation". The candidates for the next US presidential election are also getting in on the debate with Jeb Bush blaming Hilary Clinton for the rise of ISIS, and Senator Lindsey Graham warning that "if you don't do what I'm talking about, you're not serious about destroying ISIS".So is ISIS evil or does it simply use the tools of globalisation and abhorrent tactics?In John Gray's book, al-Qaeda and What It Means to be Modern, the philosopher warned that we were witnessing the growth of a "privatised form of organised violence worldwide".Closed online communities are acting as echo chambers that are corroborating world views and shifting notions of what is and isn't acceptable.Suicide bombings of the 1990s appeared in the zeitgeist of evil tactics, but the theater-managed, mass executions that ISIS specialises in show how far these tactics have developed.Seeking roots of legitimacyISIS networks flourish in a potent mix of history and conspiracy theory of Western subjugation of the Middle East that allows often vulnerable people to be attracted to the promise of a new "caliphate" that seeks its roots of legitimacy in the narrative of a glorious past.ISIS's propaganda machine, a key component in the success of the group achieving worldwide notoriety, must revel in the language used against it.Just as its flag is black and white, so is the binary that it uses of "them and us", and language-shaping images of a clash of civilisations that further encourage recruits and supporters to flock to the cause. There is an increasing need for nuance, complexity, and challenge in the debate over who ISIS is and what the right tactics to defeat it are.The straw dog of ISIS hides in the shadow of every issue political leaders want to address. In the absence of nuance, the spectre of ISIS will be conflated with the reality of an organisation, to the detriment of any coherent strategy.Indeed, while the coalition aligned against ISIS is impressive in both its scope and its language, its clear weakness is its vision for how to fight this fight beyond the short term.Ultimately, deploying the language of "evil" against ISIS is lazy, naive, and often counter-productive. What these words invoke plays into the hands of those in the group who revel in the images of their savage notoriety and are purposefully painting a picture of a millennial conflict that will last generations. A grim prospect indeed.James Denselow is a writer on Middle East politics and security issues and a research associate at the Foreign Policy Centre.The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.