Want to remember what Zine el-Abidine Ben Ali was like? Just walk down the Avenue Habib-Bourguiba – until a few weeks ago still cordoned off by armoured vehicles and barbed wire – and drop by your local bookshop for Z's wonderful Révolution! Des années mauves à la fuite de Carthage. Z always painted Ben Ali's sycophants purple; his cartoons were the joy of the revolution, Ben Ali's bloated relatives flaunting their new shopping malls while the people – 96 per cent of whom were always said to be Ben Ali's secret police – are beaten by thugs in black uniforms and shades. Ben Ali receives support even from his telephone, his lampshade and the national flag in his office until he does a bunk on his jet while flunkies load aboard chests of cash along with the ginger family cat. Even the press get a run for their money.

"The huge number of young people signing up for the Charter of Tunisian Youth demonstrates the support of young Tunisians for the reforming project of President Zine el-Abidine Ben Ali, their attachment and loyalty to their country and their willingness to contribute to the development of Tunisia..." A fictional editorial from 2009 – until you realise it really is a leader from the 29 March edition of La Presse.

Thank God for freedom, then. Saloua Rachdi's tribute to the Tunisian writers who worked courageously under the dictatorship – Plumes de mon pays – sits in the bookshop window alongside French editions of Tariq Ramadan's Islamic scholarship.

But then I'm driving in the suburbs with an old Tunisian journalist friend. "Don't tell me about liberal writers, Robert," he snaps at me. "Do you know that of all the books now published in Tunisia, 92 per cent are Islamist? Outside Tunis, the bookshops just sell school notebooks and these tracts. Don't you think we should be worried?" I tell him about Egypt – there are no military rulers like Field Marshal Tantawi in Tunisia – and the violence of Bahrain and Syria. He's a lucky guy.

But he doesn't think so. Nasreddine Ben Saida, the managing editor of the newspaper Attounisia, Habib Guizani, the editor-in-chief, and the journalist Mohamed Hedi Hidri have just been arrested for publishing a photograph of a German footballer of Tunisian origin holding his half-naked German wife in his arms. It's the old story: morality versus freedom. But the elected government (with the Islamic Ennahda Party holding 40 per cent of the October 2011 vote) has used article 121 of the penal code to detain the three journalists, a law dating back to the Ben Ali era. Mongi Khadraoui, a senior member of the Tunisian journalists' union, points out that 121 was introduced to lock up all kinds of opponents of the regime, and that, while the publication of the photo was a mistake, it "should be treated as a professional error rather than a crime."

What happened, then, to decree-law 115 on the freedom of the press, passed under last year's provisional administration? Two days before the arrests, the Ennahda Party was already being condemned by journalists' groups for supporting a free press while at the same time claiming that 115 was no longer valid. Attunisia suddenly disappeared from the news-stands.

All this might be a luxury in a country of 10 million whose 3.5 million working population now boasts a terrible 800,000 unemployed, whose Central Bank announced a growth rate of zero for 2011, which 80 international companies have already abandoned, and whose government will only last for a maximum of 18 months, the time it takes to come up with a new constitution. But this is not the only legacy of the Ben Ali years. His fawning governments poured money into Tunis and starved the countryside; and this is where the Salafists – hated by Ben Ali, amnestied after the revolution – first made their appearance.

The town of Sejnane, north-west of Tunis, witnessed, briefly, the existence of an "Islamic emirate" at the end of last year when around 200 Salafists took control, turned government buildings into prisons for "sinning" – in most cases for drinking alcohol – and beat inmates. A shop selling CDs of western songs in Arabic was set on fire and a self-proclaimed Islamist "judge" announced to the owner that "if you try once more to distract Muslims from the mosque, it will be your home and all those in it who will burn".

Women began to wear the niqab, men to grow beards and wear Afghan-style clothes. The government did nothing. Was the Ennahda Party supporting the Salafists?

Attacks on cinemas began shortly afterwards, the owner of Nessma TV, Nabil Karoui, put on trial for showing Persepolis – about the reactions of a young girl growing up in the 1979 Iranian revolution – a film deemed "contrary to the values of the people". Two intellectuals were savagely beaten and 10,000 demonstrators marched through Tunis and other cities to protest at the increase of extremism.

In the much-underrated French magazine Jeune Afrique, Amel Grami, head of the Islamic Studies department at Manouba University, described how a dispute over a female student who insisted on wearing full head-covering to college resulted in an invasion of the campus by sword-carrying Salafists, some of whom shouted "dirty whore" when staff objected to the separation of male and female students. According to Amel Grami, the Salafists were supported by two sons of the Tunisian Interior Minister, Ali Laarayedh.

Little wonder, then, that the impending arrival in Tunisia of the Egyptian preacher Wajdi Ghanim created such anger among secular Tunisians. Ghanim supports the Tunisian Salafists, advocates a return to an older, more "genuine" Islam and – in the view of human rights groups – wants to "create hatred between Tunisians". It all has the feel of Algeria before the army's cancellation of the second round of elections which would have brought the Islamic Salvation Front to power in 1992. We shall not dwell on the carnage and bloodletting that followed.

But in this context, the voice of secular Tunisia sounds familiar. Tunisia has given the world great heroes – Hannibal, Jugurtha, Ibn Khaldoun, even Habib Bourguiba – the Tunisian writer Abdelhamid Gmati pointed out. "So why do we bring here these Salafists, these Islamists, these Wahabis, these Afghanists, these preachers (sexually obsessed and probably paedophiles), who speak of the mutilation (of women), who make fatwas ... who have nothing to do with our civilisation, our idea of religion, our values which have developed over thousands of years? Sorry – but their beards, their niqabs, their robes, their blackness, their "Middle Ages" are not ours." Even if they were born Tunisian, "they are not Tunisians".