LONDON — IRISH terrorists have told police in mainland Britain to expect a sustained onslaught of terrorism in coming weeks specifically aimed at disrupting the country's faltering economy.
The first blow in the campaign was struck on Feb. 26 when bombers destroyed a huge gas-storage tank at Warrington, near Liverpool. A threat by the Irish Republican Army (IRA) that comparable attacks are planned raises the prospect of a dangerous new chapter in attempts by the terrorists to force Britain to negotiate the withdrawal of its troops from Northern Ireland.
The threat comes as President Clinton is considering the appointment of a United States peace envoy to travel to Northern Ireland on a fact-finding mission.
Earlier bomb and mortar attacks have been on public and political targets such as department stores, pubs, shopping complexes, and occasionally government offices, including 10 Downing Street, the prime minister's London residence.
But the IRA became aware of the economic havoc they could cause with a single attack when they detonated a car bomb last April at the Baltic Exchange in the heart of London's financial district, causing damage estimated at 800 million pounds ($560 million). Police say the IRA has decided to switch tactics and concentrate on economic targets because Britain's current recession makes attacks on industrial sites more newsworthy and therefore more likely to attract publicity.
Experts on terrorism add that the IRA has a record of employing tactics in England that they have already used in Northern Ireland. Eamonn Mallie, author of the book, "Inside the IRA," says attacks on economic targets in the province have been occurring for a long time. "It was to be expected that sooner or later they would apply the same methods on the mainland," he says.
LAST December, IRA bombers came within a hair's breadth of causing huge loss of life in Belfast when they planted explosive devices in an oil refinery in the eastern part of Northern Ireland's capital. The explosions were intended to ignite gas supplies and produce a fireball, but the IRA's devices did not work properly.
The attack at Warrington was more successful. The bombers destroyed a natural gas container 120 feet tall. The blast from three separate explosions produced a mushroom cloud of fire and smoke 200 yards from a housing complex.
An array of torpedo-like devices filled with high explosive and attached to a liquid petroleum tank failed to detonate, however. "If they had, most of Warrington would have been affected," a local fire service officer says.
Prof. Paul Wilkinson, director of the Research Institute for the Study of Conflict and Terrorism, says that the IRA had been encouraged by the Baltic Exchange attack to put more effort into causing economic damage.
"They calculate that the havoc they create will be an extra lever on the British government to change its policy," he says. "Disrupting commercial centers, the railway network, and industrial complexes does great harm to business and industry.
"The IRA considers that in terms of publicity one bomb in England is worth 20 in Belfast," Mr. Wilkinson adds.
After the Warrington attack antiterrorist police visited the area and assessed the methods and equipment that had been used by the bombers. Scotland Yard sources say companies with infrastructure that the IRA could regard as targets are being warned to step up security arrangements.
Potential economic targets include fuel depots, electricity and railway stations, and chemical factories.
Police privately admit that the two IRA teams believed to have planted the bombs at Warrington were able to do so without causing suspicion. Police officers later arrested a number of suspects, and on March 1 discovered a cache of arms and explosives that detectives later said appeared to be connected with the Warrington attack.