Recent debates concerning migration, multiculturalism and racism has come to revolve around what has widely come to be conceptualised as the "problem" of Muslim minorities.

However, analyses that discuss anti-Muslim discrimination and vilification in terms of racism are frequently rejected on the grounds that religious identity is about ideas rather than race, and that religious ideas (and therefore identity) are a proper topic for debate and criticism, however heated.

This line of thinking maintains that while racism is based on baseless prejudice, religious ideas should be subject to rigorous analysis and refutation where appropriate.

As Salman Rushdie puts it: "people must be protected from discrimination by virtue of their race, but you cannot ring-fence their ideas."

This distinction between "unacceptable" racial vilification and religious vilification as a necessary element of free speech leaves a space for racist language to re-emerge under the guise of theological or philosophical criticism.

The history of such recoding of racist language as religious critique (and vice versa) has been widely documented. Geoffrey Braham Levey and Tariq Modood describe the mutation of anti-Semitism from a religious to a biologically-based hatred: "The prejudice against [Jews] transmuted from a theological disputation to the blood in their veins, where what they believed or how they looked was immaterial."

Racism against Muslim migrants to Europe, Australia and North America has shifted ground in the opposite direction, with biological racism's focus on skin-colour and physical difference being supplanted by cultural and religious racism. Although coded expressions of biological racism have maintained a background presence in both public and private discourse, and occasionally erupt at full strength, there is a broad consensus around the condemnation of openly expressed racism based on physical or alleged genetic difference.

However, racism based on cultural and/or religious difference continues to stigmatise many of the same individuals and communities who were once the target of biological racism. Muslims have provided a focal point in the transition in racialised language that has been variously described as a transition from "colour" to "cultural" racism, from "Old" to "New" racism, or as the (re)emergence of religious racism in the form of Islamophobia. While some acknowledge the "variation" between these different forms of racism, they also "emphasize how the two logics of racism exist side by side, and ... are both reproduced through a similar racialization process."

Established anti-racist mechanisms, however, remain focused on "old" racism and provide insufficient resources for combating contemporary forms of essentialism. Contemporary discussions of "the Muslim problem" ascribe to Muslims a common agenda and a common stigma, which Muslims are told that they have to tolerate because it is supposedly based upon their opinions rather than their race.

Measures and proposed measures to combat the "new racism" by means of religious vilification legislation have been strongly contested because of the threat that such legislation is said to pose to free speech. In many jurisdictions, Jewish and Sikh ethno-religious identity is already protected under anti-racism legislation because Jewish and Sikh communities are considered ethnically homogenous. Muslim identity (in common with Christian, Hindu and a range of other religious identities) is not afforded such protection under antiracist legislation because the common denominator is considered to be religion rather than race.

However, Muslims living in the West have experienced the racialization of Muslim identity, both in the form by which identity is ascribed to them and in the nature of their response. Muslims have been subjected to a series of moral panics over issues ranging from terrorism to sexual violence, through to the role that they are said to play in suffocating free speech. Concepts supposedly derived from Islamic theology are often cited as evidence that Muslims are inherently hostile Others.

Consider the concept of taqiyya - or "action of covering, dissimulation" - which can be traced back to internal Muslim sectarian conflict and "denotes dispensing with the ordinances of religion in cases of constraint and when there is a possibility of harm." Defined by The Oxford Dictionary of Islam as the "precautionary denial of religious belief in the face of potential persecution," in academic scholarship it is most commonly described as a Shi'a justification for false denials of faith told as a means of surviving Sunni persecution.

Allegations of taqiyya still feature in intra-Muslim disputes, particularly those across the Sunni/Shi'a divide but also between secular and Islamist political parties. Such allegations have arisen in Turkish political discourse, where Kemalist politicians and commentators have accused religious movements and political parties of engaging in taqiyya (or "takiyye"), concealing their Islamist agenda beneath a democratic facade.

However, in post 9/11 anti-Muslim discourse, taqiyya has been redefined as a religious obligation for Muslims to lie to non-Muslims not simply for survival, but in order to serve the expansionist agenda of their religious community. According to the taqiyya-focused strand of the anti-Muslim moral panic, Muslims stand condemned for their participation in this hidden agenda even when no criminal or anti-social behaviour is apparent.

Taqiyya scare-mongering has a strong online presence and is beginning to enter mainstream media as a counterpoint to reassurances from "moderate" Muslims that their religious community poses no threat to non-Muslims. This paranoia reaches its logical conclusion with the "secret Muslim" rumours surrounding U.S. President Barack Obama. Obama's visible otherness as the first black President is not considered a legitimate target in mainstream political discourse. Instead, he is under fire for his alleged invisible, clandestine identity as a Muslim. The fact that Obama's father and stepfather were at least nominally Muslim and that he spent part of his childhood in Indonesia is cited as evidence for such claims. Despite his public identity as a churchgoing Christian, his family links with Islam have generated allegations that he is really a secret Muslim and his presidency is part of a sinister Islamic plot.

Other prominent public figures have faced equally far-fetched accusations of taqiyya. After Democratic congressman Anthony Weiner was forced to resign following revelations that he had sent explicit photographs by text message to various young women, neoconservative public relations consultant Eliana Benador speculated darkly in a blog post (later removed) for the Washington Times website on why Weiner's Muslim wife had chosen to maintain her marriage to her disgraced Jewish husband: "It is also important, when looking at this situation, to remember that observant Muslims practice Taqiyya, an element of sharia that states there is a legal right and duty to distort the truth to promote the cause of Islam."

While this is an extreme example of the racialization of Muslims, it is part of a wider trend in which Muslims are not criticised for their beliefs, as much as they are assigned spurious beliefs on the basis of a sometimes very tenuous religious affiliation.

The question of when it is acceptable or even necessary to lie has been discussed by theologians, philosophers, ethicists and etiquette columnists. Philosophers ranging from Plato to Leo Strauss have written about "the Noble Lie," while the Catholic notion of "mental reservation" outlines the provisions that may be made in circumstances where the sinfulness of lying is outweighed by the harm that would be caused by telling the truth. The circumstances in which it is permissible to deny one's deeply held beliefs in the face of persecution belong to this philosophical tradition.

Shi'a scholars responded to this situation with the now infamous provision of taqiyya. The medieval Jewish philosopher Maimonides wrote that, while it is better to be put to death than to renounce one's faith, "crypto-Jews" who publicly renounced their faith in the face of oppression while maintaining it in secret were exempt from punishment and retained their Jewish identity. The Book of Esther was another source of guidance for Jews covertly maintaining their identification with Judaism in post-expulsion Spain and Portugal: "[t]he biblical Jewish queen, who had hidden her true faith in order to save her people, became in their eyes the exemplary heroine."

At a more mundane level, contemporary media and social discourse generally hold that "white lies" told without malice are sometimes necessary in order to maintain harmonious social relationships which may be disrupted by unvarnished truths.

However, despite such long-standing provisions for lies of necessity, habitual lying also has an equally well-established history of being represented as a characteristic of various out-groups. The characterisation of Jews as manipulative liars is a deeply-entrenched anti-Semitic trope, while words like "shifty" and "devious" are widespread features of racist hate-speech against a range of targets. In some cases, this untruthfulness is represented as going beyond a shared but individually performed trait and becomes part of a covert group agenda (the "Protocols of the Elders of Zion" being the most notorious such conspiracy theory).

Muslims are the most recent out-group in the West to stand accused of engaging in theologically-endorsed lying on behalf of an ethno-religious conspiracy. Moreover, taqiyya scare-mongering extends and racializes the category of "Muslim" to include some non-Muslims whose Muslim family members and/or overly sympathetic attitude to Muslims are regarded as indications that they are "secret Muslims" who practice their religious identity covertly, not in order to avoid persecution, but in order to further the interests of jihad.

Prior to 11 September 2001, the term taqiyya received only occasional mention in Western media stories as a linguistic curiosity. In the immediate aftermath of the attacks on New York and Washington, taqiyya began to be cited by some "terrorism experts" in the Western media to explain the rationale underlying the hijackers' double-lives during their preparation-time as undercover agents.

Initially used in relation to infiltration by external agents, taqiyya gradually began to feature in discussions of local Muslim communities as potential fifth columnists. In the wake of an infamous sermon by then-Mufti of Australia Sheikh Taj al-Din al-Hilali, in which he described inadequately dressed women as "uncovered meat" that provided temptation to cats, opinion columnist Piers Akerman outlined a long list of standards to which any future Muslim leader "must" adhere:

"He must also inform non-Muslim Australians of his view of certain Koranic principles which foster division, such as the notion of al-Taqiyya, the concept understood by both Shias and Sunnis, that it is permissible to lie or dissemble to both Muslims and non-Muslims in various situations."

While still a somewhat esoteric term in the mainstream media, taqiyya has become so familiar for some sections of the tabloid audience (particularly in the United States) that writers and broadcasters now often use the word without bothering to provide a translation or explanation.

Martha Nussbaum notes the ways in which such framing of Muslims as a hidden menace echoes the history of conspiracy theories against Jews: "the claim that Muslims characteristically conceal and deceive - all this might have been taken right out of the Protocols, but for the fact that human beings are prone to such fear games, without the need for direct casual influence."

While contemporary discourse on Muslims is dominated by cultural racism, the boundary between cultural and biological racism remains permeable and fluid. The increased visibility of taqiyya scare-mongering highlights the extent to which these forms of racism are intertwined rather than discrete.

Having undergone the slippage from ethnic to religious Other, Muslims in the West now find that racism towards them is following the pattern of European anti-Semitism an ideology which saw hatred of Jews "transmuted from a damning theological disputation to the blood in their veins, where what they believed of how they looked was immaterial."

By propagating the myth of systemic Muslim deceitfulness in the name of Islamic conquest, taqiyya scare-mongering pronounces judgement upon Muslims - not based on a distorted version of their beliefs, but on their inherited or acquired membership to a collective identity.

Shakira Hussein is an Honorary Fellow at the National Centre of Excellence for Islamic Studies in the Asia Institute at the University of Melbourne.