England expects every man will do his duty.

--Admiral Nelson

. . . And with lightning speed that has far exceeded the Royal Navy's 18-knot-per-hour advance on the Falkland Islands, British Telecom--a cable computer service--has already begun offering subscribers OBLITERATE!, a video game that invites armchair admirals to wipe out the Argentine fleet.

"Your orders are to obliterate the Argentine flagship Fray Bentos," the screen reads, in letters printed over swelling blue-and-white waves, viewed from the conning tower of a sub. "The honour of the nation is now in your hands. You must succeed! UP PERISCOPE!"

The scene shifts to a view of the Fray Bentos--the brand name of a British variety of corned beef--centered in the cross hairs of a periscope. "ACTION STATIONS!"

The object here is to pick the proper combination of range and time-delay that will allow one of two "thermodynatronic" torpedoes to have all of Argentina crying for the Fray Bentos. But choose incorrectly and the computer announces:

"Your poor judgement is endangering the reputation of your country and giving the enemy chance to retaliate. Key 1 for a chance to do better." Fail again and the screen says:

"Sorry, before your torpedo reached its target, the Argentines spotted and sunk you. GLUG GLUG GLUG!" A direct hit, however, yields the image of a ship exploding in flames and the message:

"Well done, sir. You have achieved your mission to obliterate the pride of the Argentine fleet. Congratulations. You are a national hero. Horatio Nelson, the admiral who defeated the combined Spanish and French fleets off Trafalgar in 1805 would be proud of you."

Daily play of OBLITERATE! should keep national aggression properly aimed in Britain--at least until any real shooting begins.

The game was created this week by an anonymous staffer at the Manchester Evening News, which in turn placed the game on its Prestel World Service network. There are 23,000 global subscribers--18,000 of them in England--to this computer service, which normally offers commodity prices, stock reports and corporate information. Several hundred U.S. users purchase the service from the New York City firm Logica, which provides the programming over phone lines from a computer in Boston. Prestel is accessible on any Apple home computer, with the purchase of an $85 decoder disc from Logica.

"The game was really created on the fly," Logica marketing director Dick Lutz said yesterday. "It came on line a couple of days ago. It was much better developed this morning. This guy in Manchester--we don't know who he is--keeps updating it. We're told it will change as the situation in the Falklands develops. I wouldn't be surprised if we have aircraft in the game on Monday."

Harry Jackson, a reporter for The Guardian, the sister paper of the Evening News, observed yesterday:

"I'm afraid there's a terrible outbreak of jingoism in Britain. Have you heard about the dotty old lady in Wales who's dialing numbers at random in Argentina and singing 'Rule Britannia'? This game won't be the last of it."