By the Venezuelan account, it is a simple matter of repairing the damage of colonialism -- a seizure of Venezuelan territory that began when the indiscretions of a Prussian naturalist were compounded by 19th century British imperialism.

For Guyana, on the other hand, it is a case of naked threats by one Third World nation against another, threats based solely on posthumously published assertions by an American lawyer seduced by the Venezuelan government when he was old and possibly infirm.

Whatever the truth, the 140-year-old border dispute between Venezuela and Guyana over a chunk of land that now makes up two-thirds of Guyana's territory has come to be a central issue for the two countries' governments, and in recent months has escalated into a new point of turbulence and potential conflict in a continent already checkered with border quarrels.

Within the last few weeks, Guyanese Prime Minister Ptolemy Reid has traveled to the United States and other nations to denounce Venezuela and seek outside support for Guyana's position. The dispute, he said in a speech to the United Nations late last month, contains "a clear potential for threatening and indeed disturbing international peace and security."

In an interview with United Press International in Washington, distributed in Spanish, Reid was quoted as saying that while no Cuban troops are currently in his socialist country, Venezuela could launch a military effort to take the land, in which case "I don't see any reason to refuse assistance from nations that want to give it to us."

Meanwhile, the Venezuelan government, which reopened the dispute last April by announcing its refusal to extend an agreement that set the issue aside for 12 years, has been publicly lobbying against World Bank loans to Guyanese development projects in the disputed territory, including a massive hydroelectric project that Guyana considers crucial to its development plans.

Venezuelan officials insist that they will not drop the issue until Guyana agrees to negotiations that could restore to Venezuela land it maintains was stolen by Guyana's former colonial master, Great Britain.

The issue, at least on the Venezuelan side, illustrates the political imperatives of nationalism in South American countries and the consequent nature of border disputes. Typically these quarrels have grown out of European colonialism and involve swaths of unexplored or even untouched land rich in the primary resources that are fueling much of the continent's development.

While the rhetoric between Venezuela and Guyana has reached a higher pitch recently, Venezuela is also embroiled in a similar, long-running border debate with its western neighbor, Colombia, while Guyana has yet to resolve part of its border line with Surinam. Elsewhere, Peru and Ecuador and Argentina and Chile have teetered on the brink of armed conflict in recent years over control of mineral-loaded land.

At stake in the Venezuelan conflict is a large parcel of largely unexplored jungle inhabited mainly by backward tribes of native Indians. Bounded in part by two large rivers -- the Essequibo and the Cuyuni -- the area contains ample deposits of bauxite, the raw material of aluminum, as well as vast hydroelectric potential and, off the northern coast, possible petroleum reserves.

In the days of Spanish colonialism, when the Dutch controlled Guyana, the boundary of Venezuela was set at the Essequibo. That line is now more than 100 miles inside Guyana. By 1830, however, Britain had acquired Guyana and Venezuela was an independent nation, and by 1840, British miners were crossing the Venezuelan border in search of rumored gold deposits.

Between 1840 and 1843, the Venezuelans maintain, a Prussian naturalist named Schomburgk went on a series of map making expeditions. On each of his trips, according to an official Venezuelan account, he produced a map for the British government that pushed the frontier westward into Venezuela, to keep up with the intrusive miners.

By the end of the century, Britain had extended its claim far into what is now eastern Venezuela and finally posted a fleet off the Venezuelan coast in an effort to back up its demand.

But at this point, the United States -- with the Monroe Doctrine in mind -- intervened on behalf of Venezuela. Washington threatened war on Britain if it did not submit to arbitration. The U.S. secretary of state at the time, Richard Olney, said: "The United States is practically sovereign on this continent and its fiat is law upon the subjects to which it confines its interposition."

Amid such grandiose pronouncements, a tribunal was established in 1897 to resolve the dispute. It included American lawyers; a former American president, Benjamin Harrison, and the chief justice of the U.S. Supreme Court. There were high British officials and jurists from France and Russia. But, the Venezuelans now point out indignantly, no Venezuelans participated in the proceedings. Instead, their interests were left to be represented by the Americans.

The arbitration that resulted in the border of British Guyana being extended all the way to the Cuyuni River represents, in the words of one high Foreign Ministry official here, "a familiar situation -- the developed powers of the world getting together to divide up the undeveloped countries."

"We were victims of the system of colonialism that existed at the time and that in other regions extends to this day," added the official, who agreed to be interviewed on the grounds that he not be quoted by name. "Venezuela was never consulted about this division of territory , and Venezuela never has accepted it."

However, in pressing its claim, Venezuela exposed itself to similar charges of imperialistic deal-making from Guyana. The Venezuelan government began actively pressing the issue in the United Nations and with Great Britain in 1962, at the time Guyana was finally beginning the process of gaining independence. At that time, Guyana charges in its own official account of the dispute that "Venezuela launched an international campaign against Guyana the effect of which . . . would have been to prolong her colonial status."

As justification for reopening the matter, Venezuela depends on a memorandum said to have been dictated in the 1940s by an American lawyer involved in the tribunal, Severo Mallet-Prevost, and published after his death. Mallet-Prevost, who had traveled to Venezuela to be awarded the "Order of the Liberator" prior to his memorandum, claimed that the 1899 settlement of the dispute had been the result of a deal between the British and Russian tribunal members.

The Guyanese are scornful of this claim, which, it is caustically noted in a government pamphlet, involved a "junior" member of the American team who made his charge "some time after the other parties involved had departed this life."

The dispute reached a crisis in the late 1960s, and Venezuela went so far as to station troops on a disputed island in the Cuyuni before the two countries agreed to set the issue aside for 12 years. That protocol expires next June.

When Guyana's President Forbes Burnham visited Caracas last April to seek an extension and, the Venezuelans say, Venezuelan aid for the massive Upper Mazaruni hydroelectric project Guyana is planning in the disputed region, Venezuelan President Luis Herrera Campins refused.

For now, no negotiations are in sight. The United States has proclaimed its neutrality. And as for the British who started it all? A British Embassy official here replies: "We're doing what we can to avoid the whole business."