When the Berlin Wall was torn down, the Soviet Union collapsed, and China pursued market—led development, it seemed safe to assume that the threat of aggressive communism toppling national dominoes and dominating an entire continent was gone forever. But while America has focused its attention elsewhere, communism is on the move in South America, and the shape of a serious plan to dominate our neighboring continent has become evident. Even worse, our natural ally to resist such domination is strangely uninterested in defending its turf.

On a scale not seen since the 1960s, Cuba's Fidel Castro and his new ally, Venezuela's Hugo Chavez, are aggressively seeking influence all through South America. The one power that could stop them, Brazil, is strangely asleep. As a regional power, South America's largest, most economically powerful — and most ambitious — country is proving to be a disappointment, and this couldn't happen at a worse time.

Brazil's western neighbor Bolivia is about to hold a national election on Dec. 4 that could bring a third member to the Castro—Chavez axis to its leadership, a Marxist coca—growers' leader named Evo Morales. Castro and Chavez are working hard to ensure that he wins. Meanwhile, Bolivia's neighbors are subject to an intense subversion campaign as a result. How such events are resolved may determine the direction of the continent for decades.

Brazil's response so far to predators like Chavez and Castro is largely to ignore them and do nothing.

But strangely, Brazil is not extending that hands—off attitude to its much—smaller southern neighbor, Paraguay. In an odd foreign policy priority, Brazil has begun bullying Paraguay, effectively demanding that it pledge fealty to its own MercoSur trading bloc and renounce any thought of joining the U.S.—sponsored Free Trade Area of the Americas. 'It's them or us,' Brazil warned, in so many words. Brazil's Foreign Affairs Minister also demanded that Paraguay disclose all details of its military cooperation with the U.S. in a broad overreach that clearly is none of its business. This is no way to win influence, and in the past week, Paraguay has defiantly warned it's ready to walk out of Brazil—led MercoSur.

Paraguay is a small landlocked South American nation with a right—leaning government that in some ways resembles that of our strong ally, Colombia. Paraguay is no Colombia, but it moves in an interesting political counter—orbit to its left—leaning neighbors like Brazil, Uruguay and Argentina. Paraguay seeks to grow out of its poverty and understands well that the only way to do so is through foreign investment, free trade and a coherent, focused government. That resolve is one reason why Castro and Chavez are eyeing the small country.

Perhaps more importantly, Paraguay's strategic location is next to Bolivia, making it a gateway to much—larger Argentina and Brazil and their vast markets. Paraguay has a long border with Bolivia. Bolivia is on the edge of an election, one that could bring the Marxist Morales to the presidency. If Morales wins, he intends to nationalize its energy industry and communize Bolivia.

Morales and his sponsors, Castro and Chavez, have no intention of stopping there. Once Bolivia falls, Paraguay will be dealing with refugees, flows of capital flight, and the possibility of fallout from a civil war next door in Bolivia. Natural gas energy flows, which can only be transported by pipes across land, could be interrupted, affecting Brazil and Argentina severely. Whoever can control Paraguay will control the energy and trade routes from oil—rich Bolivia to Brazil and Argentina. The two largest countries in South America could be held hostage to energy blackmail.

It's clear that Chavez and Castro know all of this and are out to break Paraguay.

This year, they meddled aggressively against the small state. Castro sent in 700 "doctors" to Paraguay who tried to overthrow the government. They were expelled from Paraguay last month for this very reason. News outlets indicated that a number of Cuban operatives reportedly in the country have disappeared without renewing their visas, leaving Paraguay (and Bolivia) to wonder what they are up to. Ominously, some speculated that they may be Cuban military men on their way to Bolivia.

This wasn't the only trouble for Paraguay coming from the north. Castro's allies, the Marxist narco—terrorist FARC guerrillas of Colombia, have struck, too. About a year ago, the FARC, working with local hoodlums, directed the kidnapping and murder of a former Paraguayan president's daughter in an event that shook that nation to its core.  The FARC mastermind behind it, Rodrigo Granda, carried out his operation from Venezuela, where another Castro ally, Hugo Chavez, gave him safe haven.

To intimidate Paraguay further, Chavez's goons also beat up Paraguay's female ambassador on a Caracas street in broad daylight, after the memorial mass for Pope John Paul II. When she sought help from Chavez's foreign ministry, those officials slammed the door in her face. In addition, Chavez offered Paraguay the calculated carrot of cheap oil, something Paraguay's press recognized as a ruse to buy political influence.

Against that menacing string of events, Brazil's indifference is appalling.

Brazil hasn't done a single thing to help Paraguay against Cuban subversion and Chavista guerrillas and goons. Paraguay has been left all alone to face these predators without so much as a supportive word from Brazil, which given its size, could have an impact. That's why Paraguay is looking for other allies, like the U.S. During U.S. Defense Secretary Donald Rumsfeld's recent trip to Paraguay, the U.S. and Paraguay signed agreements on drugs, terrorism, and a small 400—troop U.S. military presence in a bid to help Paraguay with the security it obviously needs.

That U.S. support, and not the thuggery against Paraguay, hit a hot button with Brazil.

"We see no need for a base in the region," a Brazilian official said, arrogantly suggesting he knows better than Paraguayans what's best for Paraguay. Paraguay's President, Nicanor Duarte, at the UN last week, had a reply for that: "Paraguay is a small but dignified nation that has been independent since 1811."

Brazil isn't looking out for its neighbor's welfare as an authentic leader would, but seems to be thinking of itself and trying to ensure its rank as the big dog on the South American block. So it fears a U.S. defense presence in its region more than a Cuban satellite controlling its energy. If Brazil were serious about noninterference in other nations' internal affairs, it wouldn't be silent while Chavez and Castro continuously target Paraguay.

Perhaps history weighs heavily. The U.S. is a long, long way from Paraguay and forging an alliance seems counterintuitive. But the U.S. has always been viewed as a friend to Paraguay at its dark hours, ever since President Rutherford B. Hayes resolved a border dispute in Paraguay's favor in 1878. Prior to that dispute, Paraguay fought Brazil (with Argentina) in the very bloody 1864—1870 War of the Triple Alliance, where Paraguay lost over half its population, about 300,000 people, and over half its land. Memories are long.

But there's been other history since then, including 50 years of Cuban subversion across the continent, something Brazil and Paraguay both know well. It's back, and this time, it has petrodollar financing available, courtesy of Venezuela's Marxist dictator.

It is disturbing that Chavez financed a substantial portion of Brazil's President Luis Inacio Lula da Silva's election a few years ago. Could Brazil's leaders, the guiding hands of an ambitious rising power, have been bought off? Right now, Brazil is in the middle of a serious campaign finance scandal. It's possible that money has subverted Brazilian politics, pulling a regional power into the orbit of an aggressive communist movement aimed at dominating a continent.

Brazil is blessed by nature and geography with the ingredients to be the leading power in South America. But subordination of its own interest in creating a regional sphere of power to the ambitions of the last expansionist communist bloc in the world is a real possibility. And with Evo Morales leading in the Bolivian polls and poised to take power after elections on Dec. 4, Brazil doesn't have much time to get it right.

A.M. Mora y Leon is a frequent contributor.