It's hard to be shocked by news from a country where 55,000 people have died as a result of terrorism in the past decade, but yesterday's terrorist attack on a school in Pakistan has produced revulsion worldwide.

Pakistani attitudes towards the perpetrators, the Pakistani Taliban, known within Pakistan by the acronym TTP, are complex and evolving. Pew's wide-ranging public opinion survey, published in August, contains some important and disturbing findings.

At the time of the survey, 8% of surveyed Pakistanis held a favourable view of the TTP. This is a small proportion, and belies the notion of widespread popularity. Nonetheless, on a crude extrapolation, it would amount to a staggering 14 million Pakistanis. Although a much larger slice of the population holds negative views of the Taliban (59%), this disapproval rate has fallen steadily from a high of 70% in 2009, a year when the Pakistani army was engaged in intense fighting with the militants in the Swat Valley. Depressingly, it is the lowest level of disapproval in six years.

A second finding is that the TTP is still seen as the lesser of two evils. 51% of Pakistanis say India is the greatest threat to their country, while just half that number say the same of the Taliban. This is in contrast to last year; though India remained the uppermost concern in 2013, the gap had narrowed quite a bit.

More specifically, Pew's survey notes that residents of Khyber Pakhtunkhwa – the province containing Peshawar, the site of Tuesday's school massacre – see India as a greater threat than do most other Pakistanis. Imran Khan, whose party controls the provincial government there, has frequently expressed sympathetic views towards the TTP and associated militants, insisting only three weeks ago that he would not have sent the army into tribal areas.

It should also be noted that a steady stream of army-sponsored nationalist propaganda has persuaded many Pakistanis that India is, in fact, arming and training the TTP. As the journalist Omar Waraich noted on Twitter, 'the problem is less sympathy for the Taliban, of which there is little, but denial among those who believe Muslims don't do this'. One Twitter hashtag circulating yesterday, for instance, read #StopIndianTerrorismInPak.

Complicating things further, Pakistan's military establishment, and its sympathisers, have long sought to distinguish between militants deemed to be useful to the state and those considered dangerous. Only last month, Sartaj Aziz, the foreign affair advisor to Pakistan's prime minister, asked, with particular reference to the Haqqani Network: 'some (militants) were dangerous for us and some are not. Why must we make enemies out of them all?' This longstanding ambivalence has compromised the state's ability to counter violent extremism across the spectrum, particularly given the complex web of linkages between different Sunni jihadist groups in Pakistan.

How reliable is all this data? The Pew survey was conducted from April to May 2014. This was just months after government-backed peace talks and a ceasefire with the Pakistani Taliban had collapsed, resulting in a spurt of violence. It was, however, before a major military offensive by the Pakistan army into North Waziristan, Operation Zarb-e-Azb, which began in mid-June and has killed 1100 militants in four months, according to the army. It is possible therefore that the past six months of fighting have hardened Pakistani attitudes towards the Taliban, much as occurred in previous rounds of fighting, and that Pew's figures underestimate growing popular opposition.

But it is deeply troubling that, despite a stream of high-profile attacks, negative views towards the Taliban have fallen in recent years, and that a small but not-insignificant minority continue to express support. Moreover, the Line of Control between India and Pakistan has been ablaze for months, so the gap in threat perceptions between India and the Taliban might even have widened over the second half of this year.

Tuesday's attack, relatively novel in its sheer scale and its targeting of children, will undoubtedly hurt the Taliban's reputation further. That the Government has committed to continuing its military offensive, rather than pursue another ceasefire in desperation, is a positive sign. The question is whether the imagery and testimony from Tuesday – a teacher burnt alive in front of students, reported beheadings, and the Taliban's promise that this is 'just the trailer' – will serve as a catalysing moment, reversing the trend in attitudes of the past few years, or whether it will go down in history as just one more vicious attack marking a downward spiral of violence.