The Falklands War was a ten-week war between Argentina and the United Kingdom over two British overseas territories in the South Atlantic: the Falkland Islands, and South Georgia and the South Sandwich Islands. It began on April 2, 1982 when Argentina invaded and occupied the Falkland Islands (and, the following day, South Georgia and the South Sandwich Islands) in an attempt to establish the sovereignty it had long claimed over them. On April 5, the British government assaulted the islands. The conflict ended with the Argentine surrender on June 14, 1982, returning the islands to British control. During the 74 days of the conflict, 649 Argentine military personnel, 255 British military personnel and three Falkland Islanders were killed.
The U.S. affected a neutral stance in the beginning, not publicly taking sides until this day in history, when President Reagan accused Argentina of “armed aggression” in the Falkland Islands and ordered limited sanctions against Argentina.
According to the New York Times on this date, Secretary of State Alexander M. Haig Jr. warned that the Falklands dispute was entering ”a new and dangerous phase, in which large scale military action is likely,” and Mr. Reagan offered to provide British military forces in the South Atlantic with ”materiel support.” But he ruled out any direct United States military involvement.
President Reagan, speaking to a group of Midwest editors and broadcasters at the White House, placed the blame for the conflict entirely on the Argentine government, proclaiming:
We must remember that the aggression was on the part of Argentina in this dispute over the sovereignty of that little ice-cold bunch of land down there, and they finally just resorted to armed aggression. I think the principle that all of us must abide by is, armed aggression of that kind must not be allowed to succeed.”
But thirty years after the end of the war, declassified documents from the National Security Archive revealed that the U.S. secretly supported the United Kingdom during the early days of the war, in spite of its public stance as a disinterested mediator. In a conversation with British officials at the end of March, Haig declared that the U.S. diplomatic effort “will of course, have a greater chance of influencing Argentine behavior if we appear to them not to favor one side or the other.”
Thus, at a meeting in London on April 8, 1982 shortly after the war began, when Prime Minister Margaret Thatcher expressed concern to U.S. Secretary of State Alexander Haig about President Ronald Reagan’s recent public statements of impartiality, Haig said he was certain the Prime Minister knew where the President stood. We are not impartial.”
The documents released in 2012 also show that the U.S. provided Britain with substantial logistical and intelligence support from the outset of the war. At the April 8 meeting with Haig, Thatcher expressed appreciation for U.S. cooperation in intelligence matters and in the use of [the U.S. military base at] Ascension Island.” Intelligence reports on the political situation in Argentina were also regularly cabled to Britain.
As far as most of the world knew, however, April 30 was the date the U.S. finally decided in favor of Britain in the Falklands War.
You can read more about the revelations of the National Archive documents here.