Tourism is the soft underbelly of every economy, an easy target at which terrorists can strike.

Holidaymakers travel abroad to relax and unwind. They are generally innocent of the political situation of the country they visit, rarely speak the language and are almost totally reliant on the local hotel staff and guides who look after them during their stay.

Daesh (the self-proclaimed IS) has attacked tourists in Turkey, Egypt and Tunisia with devastating results. Turkey has probably done the best job of tightening security. Major tourist sites in Istanbul are now patrolled and monitored. The beach resorts to the south and west of the country have thus far escaped any terror outrage because of a strong security presence. Egypt has been less fortunate despite a heavy police presence at its Red Sea resorts and at its magnificent archaeological treasures along the Nile, which have been drawing tourists for more than 2,000 years. But the most significant victim of Daesh savagery has been Tunisia. In 2015, terrorist attacks on the Bardo museum in Tunis and then on a beach at Sousse left dozens of tourists dead and overnight killed the country’s key tourism sector stone dead.

Almost half the 3.5 million working population was involved in tourism in one way or another. Unemployment, which stood at more than 15 percent at the time of the two terror attacks, has since ballooned adding to the pressures on a society still uncertain of the political changes that came about after it triggered the Arab Spring revolutions in 2011.

Foreign governments told their nationals not to travel to Tunisia. Such official advice meant that insurance companies refused to cover package tour operators. The result has been that for two years all the cheap holidays to Tunisia’s extensive holiday resort infrastructure have stopped.

But now the UK government has changed its advice. In a move which is being welcomed enthusiastically by the tourism sector, it has said that British nationals can travel to Tunis and vacation resorts but should stay away from the south of the country and the area along the Libyan border. UK holiday firms are already marketing packages for this year. Other countries are following suit. Suddenly Tunisia’s economic prospects seem considerably brighter.

But the government in Tunis should not ignore the alarming reality that Daesh killers will see the return of tourists as a golden opportunity to strike once again and so plunge the holiday sector back into economic chaos. Since 2015, the French, Americans, Germans and British have been working to boost Tunisia’s security. British troops for instance have been training border guards and the Germans and Americans have installed sophisticated monitoring equipment along the high berm and deep ditch the Tunisians have dug along most of their border with Libya.

But there are important lessons that should have been learnt. After the Bardo attack, security was tightened noticeably in the capital. But the alert did not filter down to the beach resorts. The Sousse police chief has admitted that he delayed rushing to the scene of the terror attack because he was afraid. After the massacre of 39 mostly British holidaymakers, high profile patrols were mounted at the resorts but thanks to the urgent advice of foreign governments for their tourists to get out, they were guarding mostly empty hotels. Such a disastrous security failure must not be allowed to happen again.