To gauge the impact that yesterday's attack will have on Egypt's tourism industry, imagine a bomb exploding on a coach full of visitors outside the British Museum.
The economic consequences for Egypt will be serious. The campaign by Islamic fundamentalists against foreign visitors began in 1992, and until yesterday had killed 26. Since the most serious attack last April, in which 18 Greek tourists were shot dead outside their hotel, the security forces in Egypt had enjoyed some success in stifling the campaign. Yesterday's atrocity is certain to lead to widespread holiday cancellations.
The Foreign Office updated its travel advice for Egypt shortly after the attack. It points out that 320,000 British people visited the country last year, but says, "The latest attack shows security cannot be guaranteed." It stops short of warning British travellers against visiting Egypt - a move which would lead holiday companies to suspend all operations there.
The tour operator Kuoni, which has 280 clients in Cairo at present, has offered them the option to move to Luxor or to return to the UK. Thomas Cook Holidays has given customers booked to travel within the next week the chance to cancel without penalty.
In the longer term, travel companies' programmes will be trimmed back, and extra security provided for organised groups. American tourists, whose numbers fell steeply during and after the Gulf war, are likely to be further disinclined to visit.
Backpackers, who use local transport and stay in low-budget accommodation, have so far avoided being targeted by the terrorists. Evidence from war- torn countries such as Sri Lanka suggests that few will be deterred from visiting Egypt.
The broader danger is that more terrorist groups around the world will latch on to targeting tourists. The fashion began in the mid-1980s when the Maoist Shining Path guerrillas of Peru declared they would attack visitors. Peru's visitor numbers have still not recovered.
In Cuba, tourism has proved remarkably successful in shoring up an economy hit by the ending of Soviet subsidies and the US blockade. But the industry has been threatened by a series of bomb attacks on hotels in Havana. The most recent killed an Italian tourist.
While Cuban officials blame anti-Castro exiles in Miami for the campaign, travel companies are busily cutting prices. The grisly pattern will be repeated in Egypt: after carnage, cheap holidays are bound to follow.
Foreign Office Travel Advice Unit: 0171-238 4503, or fax 0171-238 4545; on the Internet, at http://www.fco.gov.uk/ or on BBC2 Ceefax from page 470.Reuse content