South America.

• Position: 2014 America's Challenges - Statistical data

Venezuela

President Nicolas Maduro (above) was elected last year after the death of longtime President Hugo Chavez. Maduro has continued the repressive and anti-American policies of his Socialist predecessor, and relations with the U.S. remain tense. Crime and shortages of food and basic goods continue to plague oil-rich Venezuela.

The Amazon

Stretching across 2 million square miles in nine countries-including Bolivia, Brazil, Colombia, Peru, and Venezuela-the Amazon is the largest tropical rainforest in the world. It continues to shrink due to extreme weather and man-made deforestation (above). That's raising alarms among many scientists because the Amazon plays a key role in mitigating climate change by soaking up carbon dioxide.

By the Numbers

20% Percentage of the world's oxygen produced in the Amazon

SOURCE: AMAZON CENTER FOR ENVIRONMENTAL EDUCATION AND RESEARCH

Colombia

After almost 50 years of fighting between the government and a rebel group known as FARC, President Juan Manuel Santos is close to reaching a peace agreement. Colombia is a major American ally in the region, and the U.S. has spent more than $8 billion to help the country battle drug cartels, which provide most of the cocaine flowing into the U.S.

Brazil

The largest economy in South America and increasingly a major player in the world, Brazil is still beset by poverty. As the country gears up to host the 2014 soccer World Cup and the 2016 Olympics, it has spent millions to build facilities. That's sparked protests against inequality and political corruption in several big cities.

By the Numbers

$12,100 Brazil's per capita GDP (U.S.: $50,700)

SOURCE: THE WORLD FACTBOOK 2073 (C.I.A.)

South America URBAN AREA (SQ. MI) POP. % CAPITAL COUNTRY POPULATION POP. RISE % YEAR Argentina 1,073,520 93 Buenos 41,300,000 1.1 Aires Bolivia 424,164 67 La Paz 11,000,000 1.9 and Sucre Brazil 3,287,612 85 Brasilia 195,500,000 0.9 Chile 291,930 87 Santiago 17,600,000 0.9 Colombia 440,831 76 Bogota 48,000,000 1.4 Ecuador 98,985 67 Quito 15,800,000 1.7 Guyana 83,012 28 Georgetown 800,000 1.4 Paraguay 157,048 62 Asuncion 6,800,000 1.8 Peru 496,225 75 Lima 30,500,000 1.5 Suriname 63,251 70 Paramaribo 600,000 1.1 Uruguay 68,679 94 Montevideo 3,400,000 0.4 Venezuela 353,841 89 Caracas...