Addressing the nation outside No 10 Downing Street on Sunday morning, the prime minister spoke forcefully about the need for change, both in society’s tolerance of extremism and in the government’s counter-terrorism strategy.

In the face of three successful attacks and five disrupted plots over the past three months, that would seem an appropriate response, and most people would agree with her that “enough is enough”. But it is not yet clear what she intends to do to translate that sentiment into effective action, and she could just as easily make things worse. The greater the securitisation of our society, the longer the fear and impact of terrorism will last.

‘Blame the internet’ is just not a good enough response, Theresa May | Charles Arthur Read more

Theresa May took office in 2016 after six years as home secretary, and has been at the heart of British counter-terrorism policy since before the rise of Islamic State. She has overseen the development of the government’s Prevent strategy, which is designed to engage the public sector in spotting extremism and reporting it to the authorities.

I have been dealing with terrorism since before 9/11, and it is distressing to see that despite the enormous effort and the huge amount of money expended worldwide, this threat is indisputably greater now than it was in 2001. It is fair to question whether a more determined approach to more or less the same policies will make much difference.

A survey I conducted over the past two years, of 43 prisoners from 11 countries who had fought with extremist groups in Syria, found that a common reason for joining the fight was a sense of duty to coreligionists who were believed to be suffering from foreign or state oppression. The extremist groups had been able to wrap individual dissatisfactions with life into a communal narrative about purpose and heroism in defence of religion.

The prime minister must be careful, therefore, in equating terrorism with Islamist extremism. Whatever comment she added about the true values of Islam, this juxtaposition of terms is too simple a description for such a complex phenomenon: May’s use of words plays to the binary division that terrorists try to create between Muslims and the rest. In talking to officials in Muslim-majority countries about common approaches to terrorism, or to individual Muslims about defeating the terrorist narrative, I have almost always found criticism of the way the west approaches the problem in two areas.

First, officials complain that western governments tolerate extremist speech directed against these Muslim-majority countries because it does not contravene the law and falls under freedom of expression. This may be true, but it is totally defensible. The protection of individual freedoms, and the rule of law, are fundamental to a healthy and united society.

Second, they complain that western counter-terrorist policies in conflict zones are often counterproductive, especially when bombs and drones kill civilians. This is also true, but is far less defensible. Military action is not an appropriate response to the terror threat unless it forms part of a far wider strategy that takes into account the various drivers of extremism. The strategic counter-terrorist objectives of our military involvement in Syria are as obscure as they were in Libya, Iraq and Afghanistan.

The prime minister must be careful in equating terrorism with Islamist extremism

Terrorists aim to provoke a reaction both from government and from society, and in urging the public sector and communities to be more robust in stamping out extremism, it is essential that anti-Muslim hate groups are not given an ounce of legitimacy. Intolerance can all too easily lead to more intolerance, at both ends of the spectrum. And, as May said, terrorism breeds terrorism. Lessons from the campaign against racism may help design legislation, as she suggested, but they also show how hard it is to heal social divides. Far-right racism is still very much alive despite a consistently bad press and considerable legislation and policing since the end of the second world war.

May raised again the need to deny extremists a safe space on the internet. It is a laudable goal, but there are many problems, both legal and technical. The US first amendment protections of freedom of expression make the line between legitimate and illegitimate speech hard to draw – and in the effort to stamp out incitement to violence we should not constrict the right to express radical views. Technically, the market demand for stronger encryption will always mean that the authorities are playing catch-up. In any case the right to privacy is also important, and service providers should not be asked to infringe it except in accordance with the law. Effective legal control of the internet cannot exist outside an international convention – but, even were it possible to conclude one, its enforcement would be beyond current political and technical capacity.

Security services and police forces are not clamouring for new laws, and they already have promises of more resources. Most professionals, however, agree on the need for more intelligence, both on who may be contemplating an attack and on why.

The threat will be there for many years beyond the physical destruction of Isis and al-Qaida bases. It is dealing with the ideology behind them that presents the longer-term problem.