The US feared the Thatcher government "had not thought much about diplomatic possibilities" for resolving the Falklands crisis when it dispatched a military taskforce 30 years ago, and predicted the conflict would be a "close-run thing" that could well bring about Margaret Thatcher's fall, according to newly declassified American diplomatic cables.
The Falklands crisis was a 1982 limited war between Argentina and the UK resulting from a dispute over the sovereignty of the Falkland Islands which lie east of Argentina.
The documents also highlight American worries that a protracted war could draw in the Soviet Union on Argentina's side, with far-reaching geopolitical repercussions in the area.
To try to ensure that did not happen, the Ronald Reagan administration provided the Thatcher government with covert support, while outwardly portraying itself as neutral.
Reagan dispatched his secretary of state, Alexander Haig, to try to hammer out a compromise. On April 9, he reported that the mission would be a "very steep uphill struggle".
The state department's intelligence bureau wrote: "If Thatcher fails to redeem her reputation and the nation's honour, she could be finished as a Tory leader and PM."