In what is, these days, a rare display of bipartisanship, both major parties are running from the idea of a federal royal commission into the Catholic Church’s sexual abuse of children, its cover-up of crimes and protection of child abusers.

Undoubtedly many people calling for a royal commission are doing so because they believe it will damage an institution much reviled by progressives, regardless of whether it will assist victims of child abuse and bring the perpetrators and their protectors to justice.

But the case for a federal royal commission is compelling.

Under the Howard government, royal commissions were innately political. That government launched an investigation of the construction industry as part of its war on trade unions in 2001, justified by John Howard on the basis that “there have been many detailed allegations involving intimidation, involving standover tactics, involving threats of force and violence” (observations that might equally apply to what many churchmen did to children).

Later, mired in allegations of corruptions over AWB, Howard was forced to call a pseudo-royal commission into the wheat bribery scandal, carefully limited to make sure it couldn’t examine corruption by his ministers or the Department of Foreign Affairs and Trade. Political pressure also forced him to call one into the HIH collapse, albeit on the pretext of legal advice that the Australian Securities and Investment Commission had a conflict of interest.

Traditionally, however, royal commissions — think Aboriginal deaths in custody, or British nuclear tests, or the Stewart and Costigan royal commissions — dealt with matters beyond the remit of the criminal justice system, government policies that in retrospect were profoundly wrong or that reflected such systemic and pervasive wrongdoing that the criminal justice system was inadequate to the task of effectively investigating it. State-level royal commissions have similarly focused on issues that reflect such extensive and systemic problems that regular institutions are unable to cope with the task of investigating them, frequently because key institutions such as police forces were at the centre of them.

This history provides the core reasons why a federal royal commission, or inquiry with royal commission-like powers, is the only appropriate mechanism for addressing child abuse by the Catholic Church.

1. Existing institutions are not up to the task. The criminal justice system can only prosecute individual incidences, or individual perpetrators, of abuse. The institutional arrangements that enabled the cover-up of offences and the protection of offenders is beyond the direct scope of trials of paedophiles. Moreover, the criminal justice system, with its focus on prosecution, creates an adversarial environment that is confronting and painful for victims. A royal commission, which specifically cannot make judicial findings about individuals, can provide a more comfortable environment for abuse victims to tell their stories.

And existing state inquiries, such as the Victorian parliamentary inquiry and the newly-announced NSW inquiry into child abuse in the Hunter region, are ultimately ill-equipped to deal with an international institution. The Catholic Church operates on a global level, able to transfer paedophiles and their protectors out of jurisdictions — whether regional or national — where their activities have come under scrutiny, and operating under instruction from a controlling entity that poses as a nation-state, the Vatican.

2. The Commonwealth and other governments have subsidised offending institutions. The Commonwealth and state government, via the tax-exempt status of religious institutions, funding for Catholic schools and contractual relationships in areas like employment services, have subsidised the institutions in which child abuse, and the protection of paedophiles, has occurred. Any royal commission must address the sources of financial support for processes of abuse facilitation, including government funding.

3. It is the culture of abuse and cover-up that must be investigated. While existing processes and cases focus on individuals — the offenders, those who protected them or, from a media standpoint, high-profile church leaders like George Pell — the issue of most relevance to victims and their families is surely not merely bringing offenders to justice, but investigating the institutional culture that facilitated abuse and its cover-up, including the refusal to take victims seriously and identifying the systemic causes of it, rather than focusing on any single individual.

An inquiry such as a royal commission, which specifically lacks a determinative power such as that possessed by judicial bodies, is much better placed to explore cultural and systemic issues than courts, which focus on single instances. Without an inquiry into the “abusegenic” culture of the Catholic Church, there can ultimately be no full justice for its victims; the account of what happened to tens of thousands of people at the hands of paedophiles, and then the insult of having their abusers protected, will remain only partial.

A federal royal commission or royal commission-like inquiry is the only mechanism that will be able to provide some sense of justice and comfort to victims. But it won’t be a rapid process. The Irish Commission to Inquire into Child Abuse was established in 1999 and didn’t issue its mammoth, and truly sickening, report until 2009. That inquiry had wide-ranging terms of reference and dealt with institutional arrangements in which the Catholic Church was far more deeply embedded than in Australia. But nonetheless, major royal commissions in Australia have a history of being repeatedly extended, and it is unlikely this would be any different.

However, it is likely major party politicians will remain reluctant to support a royal commission. That probably reflects not so much any sectarian bias as an unwillingness to confront an institution that, for most politicians and particularly House of Representatives MPs, is one they deal with on a routine basis as part of their electoral duties. It also reflects the simple political equation that the victims of abuse are relatively politically powerless, while the institution that abused them remains a potent political foe if roused. It takes a lot for justice to trump political calculation.