London — The prime minister of the United Kingdom put her black alligator bag under the table, picked up a black ball point pen, set a block of white jotting paper at her right hand, and proceeded to sound a lot like President Reagan, whom she is to visit in Washington Feb. 26-28.
Margaret Thatcher will have at least one request: She said she would like to see better ways of consulting with Washington more quickly when a crisis like the Soviet invasion of Afghanistan erupts. "I doubt whether it needs new machinery," she said, "but it's a question of making sure certain events spring into action.
"We were all a little concerned that at the time of Afghanistan it was over Christmas  and we were all a little bit slow in responding and we do not wish that to happen again."
But that point apart, she indicated to American correspondents in a 45-minute session at Downing Street Feb. 16 that she shared Mr. Reagan's basic views on the Soviet Union, the crisis in Poland, and the neutron bomb.
She reaffirmed a "special relationship" between the UK and the US and agreed that the closeness between her views and Reagan's contributed to a "particularly happy relationship" between London and Washington.
It was good, she said, that she and the American President shared views on some extremely important issues, adding with typical flair," We are both right!"
And on the main topic here in Britain -- when and if the battered economy -- she was as defiant as ever.
Seemingly unbowed by figures showing more than 2.4 million people out of work , and industries closing down at a record rate, she threw her head back, fixed her questioner with a pair of steely blue eyes, and declared:
"I shall carry on believing firmly that the policies I have are the only ones that can cut through this" -- and she tapped her pen on a document showing the rise in both inflation and jobless rates between 1951 and 1980.
Mrs. Thatcher is a remarkable woman and a remarkable politician who knows her own mind and speaks it, seeming to thrive on a deeply held conviction that only her kind of attack on inflation can enable Britain to emerge from the current worldwide recession able to compete abroad.
As she came into the conference room of No. 12 Downing Street adjoining her own residence, she projected the qualities of discipline, meticulous attention to detail, razor- sharp intelligence, and a degree of impatience with positions she considers not as well-thought-out as her own.
She had not a hair out of place. She wore a dark green-and-blue-striped dress and three strands of pearls, and combined an air of authority with an occasional flash of humor.
Her critics say she is too cold, too outwardly unconcerned with the plight of the unemployed, the miners, the blacks, the elderly. She replied recently, "It's like a nurse looking after an ill patient. Which is the better nurse -- the one who smothers the patient with sympathy and says, 'Never mind, dear. Just lie back. I'll look after you,' or the one who says, 'Now come on, shake out of it'?"
Veteran observers here say she is more relaxed now than before she took office, despite the enormous problems the country faces. She is absolutely certain she is right, she dismisses polls showing that her support has fallen to about 31 percent by saying she is used to encountering problems between elections. (The next one is not due until 1984.)
Asked about the enhanced radiation warhead (often called the neutron bomb), she defended it as an antitank weapon for use against Warsaw Pact armor. Previously she had told the House of Commons she doubted it would ever be deployed in Britain, but clearly supports its use in Western Europe.
In reply to a question by this correspondent, she said defense spending in Britain would rise by 8 percent in real terms between May 1979 and May 1982. The recession means that defense contractors are hurrying to complete orders faster than otherwise, to keep their men employed.
Mrs. Thatcher repeated her views on detente, that it must by "a two-way business."
"You have to make a dispassionate assessment of your enemy. You hope very much for detente. Of course you do. The Western world is very, very peace-loving. But [1975 Nobel Peace Prize winner Dr. Andrei] Sakharov was sent to Gorky. Yuri Orlov [human rights dissident now serving a long jail sentence] -- you have seen how he was treated. You cannot expected [detente] to go on being one-way."
On the economy, she hammered on the Reagan line that public spending should be reduced in favor of letting the private sector produce more wealth. Reagan, she said, "is not burdened with the enormous nationalized sector that I have. He's fortunate."
She pointed to figures showing the annual inflation rate now down to 13 percent (7.5 percent measured over the last six months alone), and listed a number of steps she was taking to cushion the effects of massive unemployment: new state aid to BL (British Leyland) cars, regional aid to places hardest hit by lack of jobs, training programs for 440,000 y oung people.