In her memoirs, Mrs. Thatcher, who died in April, described how dismayed and let down she felt by what happened in Grenada, which retained Queen Elizabeth II as head of state when it became independent in 1974. Mrs. Thatcher summarized and even quoted from the documents released this week, but their full publication gives a detailed picture of what she described in her book as an “unhappy time” of discord a year after more serious diplomatic tension with the United States over Britain’s military effort to recover the Falkland Islands after Argentina invaded.

On the evening of Oct. 24, 1983, two messages were sent by Washington, hours after a British minister had told Parliament that there was no indication of an imminent American invasion. The first message said that the United States was considering a request from some Caribbean nations to intervene; the second, sent within four hours, said that it had decided to go ahead. Replying, Mrs. Thatcher said that Mr. Reagan’s decision “causes us the gravest concern” and warned that the queen’s representative on the island, the governor general, had told a British official that if there were an intervention, “he would probably be killed.”

“I cannot conceal that I am deeply disturbed by your latest communication,” she wrote to Mr. Reagan, adding that she hoped “that even at this late stage you will take it into account before events are irrevocable.”

The invasion took place the next day.

In an apologetic, 15-minute phone call on Oct. 26, Mr. Reagan, according to a British diplomatic note, began by saying that “if he was in London he would throw his hat in the door first” — an expression suggesting he would check to see whether or not he was welcome.

“He very much regretted the embarrassment that had been caused,” the document said, giving the president’s account of how “he had been woken at three o’clock in the morning when on a so-called golfing vacation” with a request to intervene, and emphasizing how “lives were at stake” because of the risk of leaks. “The military had only a matter of hours,” he said.