EUROPE : The IRA Takes Aim at a Soft Underbelly : With recent spate of disruptive bombings, the group has shifted its focus from heavily policed Belfast to vulnerable London.

Once again, the Irish Republican Army is inflicting its trademark terror on the streets of London.

In the second week of October alone, eight targets in the British capital have been bombed, leaving one person dead and more than a dozen wounded.

The fatal attack occurred at lunchtime in a Covent Garden pub, in the charming theatrical district in central London frequented both by young office workers on their noontime break and by foreign tourists. A customer was killed and several were wounded by a bomb set off in a toilet.

The upsurge in IRA violence has led police to warn that the terrorist campaign in the capital might continue through the economically important Christmas season--and perhaps longer.

Disrupting London is a relatively easy task: All it takes is a phone call, warning of a bomb in a busy railroad or subway station, to shut down public transport while the area is sealed off and a painstaking search conducted.

The IRA’s current strategy, according to police and intelligence sources, is to shift its focus from Belfast, the heavily policed capital of Northern Ireland, to “soft” targets in higher-profile London.

“The objective is to direct attacks against the British public and government while continuing some activities in Northern Ireland,” commented Prof. Paul Wilkinson, director of the Research Institute for the Study of Conflict and Terrorism here.

“They still have blind faith in violence as a way to make Britain submissive to their goal: to replace the government in Northern Ireland with one of their choice.”

The IRA, in a statement this week, said it would continue its attacks “until the British declare their intention of withdrawing from Ireland.”

According to estimates cited by Wilkinson, it costs London $75 million each time its routine is disrupted by a bombing or a bomb scare or hoax.

Thus, he says, the choices of targets appear almost random, switching from military barracks or police stations to government sites and civilian locations, but the intention is always the same: to keep Londoners off guard.

Most experts say that IRA campaigns have followed no fixed pattern: In the 1970s, the group bombed busy pubs--often patronized by soldiers--in outlying cities. In the past, the IRA has selected such prominent targets as Harrods department store in London, the horse cavalry in Hyde Park and a military band in Regent’s Park.

Authorities give little credence to the IRA’s claim that it often alerts police before a bomb is to go off.

“They may or may not call,” said one official in Belfast. “They never give proper details that would give us the time to find a bomb before it explodes. I think they don’t mind killing people. We’re lucky more deaths have not occurred.”

As Commander George Churchill-Coleman, head of Scotland Yard’s anti-terrorist squad, said of the Covent Garden blast: “This bomb was aimed at killing and maiming. We didn’t stand a cat in hell’s chance of stopping it going off.”

Last February, a bomb at London’s Victoria Station injured 29 people. In April, the IRA hit London’s financial district--after business hours--with the biggest bomb detonated since World War II, killing three people, injuring 91 and causing extensive damage.

Frustrated over police failure to curb terrorism, the government recently gave the leading anti-IRA role to the Security Service, or MI-5, Britain’s counterespionage agency.

A recent shift to smaller bombs, police sources say, may indicate that IRA units in England have run short of weaponry, particularly since a raid on a house in August uncovered a massive cache of homemade explosives.

Concerned lest the bombings have the IRA’s desired effect of wrecking morale, Churchill-Coleman advised Britons: “These things are going to happen from time to time. Whatever you do, do not be deterred from going about your normal business--that’s what the terrorists want you to do.”

Most Britons have responded to the bombings as they did to Hitler’s blitz--with defiance.

As an editorial in the Daily Mirror said of the IRA: “They are fearful of further dwindling support. They must know that whatever they do, the British people will not bend the knee.

“Today, and every day, it will be business as usual.”