LONDON (Reuters) - Britain's former Prime Minister Margaret Thatcher wrote an emotional letter to U.S. President Ronald Reagan during the 1982 Falklands War calling him the "only person" who could understand her position, formerly secret documents showed on Friday.
Newly declassified files from 1982 lift the lid on contacts between the two leaders over the crisis and reveal the extent of the pressure Thatcher felt she was under when Argentina invaded the remote South Atlantic archipelago to reclaim what it said was its sovereign territory, triggering a 10-week war.
In one file, the tough, outspoken Thatcher called the build-up to the Argentine invasion the "worst, I think of my life", while letters to Reagan from the time show her reliance on the U.S. president and their close working relationship.
"I am writing to you separately because I think you are the only person who will understand the significance of what I am trying to say," Thatcher told Reagan in one letter, saying the principles of democracy, liberty and justice were at stake.
Britain held its breath when Thatcher dispatched a naval task force to the British-ruled Falkland islands following the Argentine invasion. Despite losing several warships, the British eventually reclaimed the South Atlantic islands 74 days later. Some 649 Argentines and 255 British troops were killed.
Elsewhere, the files show that Thatcher stressed the special relationship between the two countries as she requested Reagan's help in a letter signed off with "Warm personal regards, Margaret".
"I also believe that the friendship between the United States and Britain matters very much to the future of the free world," she wrote.
The files provide a unique perspective on the first and only female British prime minister's personal feelings as she waged war against Argentina, contemporary records specialist Simon Demissie told Reuters.
"You really hear how personally strained she was, how surprised she was. Her voice really comes through - her sense of shock that she would have to send forces to the other side of the world," Demissie said.
"We get a sense that she is as decisive as ever and that is something which really appealed to the military officials close to her," Demissie said in reference to minutes from the War Cabinet meetings ahead of the crisis, which were also released on Friday.
Secret for 30 years, the files reveal Thatcher's political maneuvering during other events in 1982, including the Iran-Iraq war, the imposition of military rule in Poland and the Israeli invasion of Lebanon.
They also show that British attitudes to its U.S. ally were less deferential than the prime minister's letters to Reagan suggest.
In a transcript of a telephone conversation between Thatcher and her foreign minister, the prime minister criticized Reagan's communication style, describing a message from the president as "so vague I didn't think it was worth reading when it came in at half-eleven last night".
In another file, she noted "the US just does not realize the resentment she is causing in the Middle East", while a Foreign Office briefing on Reagan described the actor-turned-politician as "knowing much less than he seems to".
However, one document showed how deeply indebted British officials felt to the United States for its "clandestine help" during the Falklands war; help that the United States was anxious be kept secret.
"The US have made it clear that they do not wish to reveal publicly the extent of the help with which they are providing us. They are very much worried about the effects on their relations with South America. We must accept this as a fact of life," a Ministry of Defense letter said.
The United States assisted Britain with intelligence and communications facilities as well as with military equipment such as munitions, the document said, confirming information already in the public domain.
Emblazoned with the words SECRET and CONFIDENTIAL, many of the 6,000 declassified files will prove a treasure trove for history students keen on ferreting out hitherto unknown details of the major political events of 1982, said records specialist Demissie.
"Everything comes out in the end," he said.
(Reporting By Alessandra Prentice; Editing by Andrew Osborn)