Venezuela's President Nicolas Maduro, right, and Cuba's President Raul Castro attend an ALBA alliance summit in Caracas, March 17, 2015. REUTERS/Carlos Garcia Rawlins

For more than 50 years, tensions between the US and Cuba have influenced relationships throughout the Western Hemisphere.

Since the late 1990s, Venezuela has been solidly in Cuba’s camp, joining with the isolated island nation to push back against American influence in the region.

However, that may start to change now that Cuba is repairing its long-strained relationship with the US.

Recently, Cuba has started making friends with Venezuela's enemies — a development that could create a rift between the former friends.

Regional solidarity

After Hugo Chavez rose to power in Venezuela in 1999 on a wave of popular favor, his socialist government soon linked with the socialist Fidel Castro government in Cuba.

The two countries cooperated on a number issues, with Cuba becoming an important member of Venezuela's oil-sharing efforts. As part of those efforts, Venezuela supplied oil to Cuba in return for assistance on a number of social, military, and economic programs.

The camaraderie between Chavez and Fidel Castro was well known, and the assistance Venezuela granted Cuba was extensive.

The elder Castro brother has remained friendly with Chavez’s successor, Nicolas Maduro.

Venezuelan President Hugo Chavez, center, poses with his Cuban counterpart Fidel Castro and acting President of Cuba Raul Castro, right, in Havana in this photograph, which was taken on August 13, 2006. REUTERS/Estudios Revolucion-Granma/Handout

New friends

In one of the most dramatic developments in Cuban-American relations since Fidel Castro seized Havana in the late 1950s, US President Barack Obama announced on December 17, 2014, that the US was “changing its relationship with the people of Cuba.”

In the months since, US-Cuban relations have quickly thawed.

Cuban President Raul Castro and President Barack Obama AP

American journalists have traveled to and reported from Cuba. Airlines and cruise ships have increased their operations there, and tourist visits to Cuba increased 36% in the first five months of this year.

The US embassy in Havana, shuttered since the 1950s, has reopened, and high-ranking US officials have visited the island for further talks.

Meanwhile, Venezuela’s relations with the US have remained strained, if not outright antagonistic. Over the past year, the US leveled sanctions against the Venezuelan government. Maduro’s administration responded with fiery rhetoric and public demonstrations.

The “insolent Yankees … already know where they need to put the sanctions,” Maduro said in December 2014, just a few days before Obama’s announcement about Cuba.

The US is not the only Venezuelan foe Cuba has warmed up to.

The island nation has played an important role in the ongoing, and increasingly successful, negotiations between the government of Colombia and the country’s left-wing rebels, the FARC.

Cuba's President Raul Castro (C) stands as Colombia's President Juan Manuel Santos (L) and FARC rebel leader Rodrigo Londono, better known by the nom de guerre Timochenko, shake hands in Havana Thomson Reuters

In recent days, current Cuban President Raúl Castro presided over a historic agreement between the two sides: An accord on transitional justice that also helped set an official date for a peace deal to end Colombia's more than 50-year civil conflict.

"It is our duty" to continue contributing to the peace process, Castro said.

This agreement came as relations between Venezuela and Colombia remain on uncertain ground — particularly on their shared border, parts of which have been closed and which has been the site of a recent massive dislocation of people.

Most recently, Castro had a cordial meeting with the president of Guyana, David Granger.

An English-speaking country of less than a million people, Guyana is not a power player in the region, but it has been clashing with Venezuela over a large and long-disputed territory in Guyana.

Guyanese territory claimed by Venezuela, show in red and green. Wikipedia Commons

Maduro may be playing up the dispute with Guyana due to his need to win popular support ahead of crucial elections. As The Washington Post noted in a headline this summer, "Taking land from Guyana might be the one thing all Venezuelans can agree on."

While the Venezuelan and Guyanese leaders met on the sidelines of the UN General Assembly this week, Granger said his only interest was in a legal resolution to the dispute.

“Venezuela has not introduced any new evidence [for its claim], and I'm not interested in a photo opportunity," Granger said. “I’m interested in (the) Venezuelan removal of its claim …”

When it came time for Granger to meet with Cuba’s Castro, his feelings were evidently different:

A single meeting at a large international forum does not necessarily signal that Cuba and Guyana have ascended to a new stage of international friendship.

However, observers in Caracas have likely noticed it as the latest development in a unsettling trend: A vital ally may be drifting away from the revolutionary Bolivarian Republic of Venezuela.