The prevailing mood in both Britain and Argentina is one of exhilaration, not foreboding, at the prospect of war over the Falkland Islands.
To neither side is there much of the comic-opera element about the encounter which many outsiders attribute to it. The fact is that on both sides, deep, usually hidden, elemental feelings are engaged that go back 400 years--even though Argentina was born only 150 years ago.
Passions on both sides have been roused today because the Falklands dispute has revived the centuries-old clash between English-speaking and Spanish-speaking cultures. That was decided geopolitically in favor of the former by England's defeat of the Spanish Armada in 1588.
But the residue of animosity from that original collision has not been completely purged, even though France and then Germany later challenged Britain's mastery of the seas and expansion of empire.
It is worth noting that all members of the ''old'' Commonwealth have reacted in their own way to Argentina's seizure of the Falklands. New Zealand has broken diplomatic relations with Argentina. Australia and Canada have recalled their ambassadors from Buenos Aires for consultations, and Australia announced that it was considering diplomatic and trade sanctions against the Argentines.
Some outsiders are comparing the Falklands crisis of today to the Suez crisis of 1956. Certainly nothing since Suez has roused the British as much as Argentina's seizure of the Falklands. But a more apt comparison would be the events leading up to the War of Jenkins' Ear in 1738--a war on a European scale that led into the subsequent War of the Austrian Succession.
Then an outraged English master mariner, Robert Jenkins, back from the Caribbean, confronted an almost pathologically anti-Spanish House of Commons with an amputated ear. The ear, he charged, had been torn from him by men of a Spanish naval patrol who had boarded his ship, the Rebecca, on the high seas. The English parliamentarians bayed for Spanish blood --and went to war the following year.
Today's emotion-charged atmosphere in the British Parliament recalls the tensions there nearly 250 years ago. The outcome of the current crisis may not follow that of 1738. But after a Cabinet meeting April 6, parliamentary correspondents in London reported that while Prime Minister Margaret Thatcher was hoping for some diplomatic resolution of the crisis before the British fleet arrived at the Falklands in two weeks' time, the threat of force against Argentina would be maintained.
It may seem strange to outsiders that the future of 1,800 on a group of barren, rocky islands far away in the South Atlantic should shake a Britain that until now had seemed only too willing to divest itself of empire. The crisis has already cost Foreign Secretary Lord Carrington and his two principal subordinates their jobs. Mrs. Thatcher's own future might well be at stake--as indeed might that of Argentine strongman President Leopoldo Fortunato Galtieri.
One comes back, however, to the elemental clash of those two originally European cultures. Most Britons are at least dimly aware that their ancestors' defeat of the Spanish Armada kept the door open for the liberating consequences of the Protestant Reformation, for the glories of the reign of Elizabeth I, for Shakespeare and the King James translation of the Bible. It opened the door for the colonization of English-speaking North America and its subsequent history.
The other side of the coin is the sense of humiliation so often felt by the Spanish-speaking culture, outmatched (at least by force of arms) first in 1588 and ever since in material and social development in the New World. It doesn't matter that the population of Argentina includes a bigger proportion of people of British origin than any other Latin American country. That community has for the most part persisted in feeling itself superior to other Argentines, thereby perpetuating old prejudices.
Few can put people down as crushingly as the British. Labour's opposition spokesman John Silkin described Argentinian President Galtieri in Parliament at the weekend as ''a bargain-basement Mussolini.'' Labour leader Michael Foot said any guarantees given the 1,800 English-speaking Falklanders by the Argentine Government were ''as worthless'' as any given ''by this same junta to its own people.''
The obduracy of this centuries-old cultural antagonism is reflected in the persistent disputes between Britain and Spain over Gibraltar and between Britain and Spanish-speaking Guatemala over the future of the Central American English-speaking state of Belize, now a member of the Commonwealth.
Relations between the English-speaking US and the Spanish-speaking Latin American countries also carry with them echoes of the animosity involved in the collision of the two cultures.
It complicates the US role as mediator between Britain and Argentina.
Mrs. Thatcher's Conservative government has been more supportive of President Reagan's policies than any other European member of the alliance. It was the only European government which responded to the US invitation to send observers to watch last week's election in El Salvador. British public opinion is likely to expect a matching measure of support from Washington now that a British interest is at stake in the hemisphere.
But any too close an association of the Reagan administration with the British could drive Latin American support as a whole into more solid backing for Argentina--and produce a wave of anti-US sentiment.
This all falls at a time when Mr. Reagan has been seeking support in Latin America for his policies in Central America. Argentina, in particular, has reportedly been considered a source of manpower in plans for covert operations in the region.
In addition, if Washington took sides with Britain against Argentina, an opportunity would open for Soviet exploitation of the crisis. Moscow already has a debt to Argentina: the latter helped supply the Russians with wheat when President Carter began the grain embargo against the Soviet Union as a protest for the Soviet invasion of Afghanistan in December 1979.