For decades it was one of Washington's closest alliances.
United in their fight against drug trafficking, Colombia and the United States co-operated closely, with the latter receiving hundreds of millions of dollars in US military assistance annually.
But now that alliance appears be more fragile than ever.
The leaders of the two countries may have a similar style - forceful and not prone to mincing their words - but left-wing Gustavo Petro and Donald Trump come from opposing ends of the political spectrum and have clashed frequently since Trump returned to the White House in January.
On Sunday, tensions reached their highest point when Trump accused Petro of encouraging drug production in Colombia and announced the suspension of payments and subsidies to the South American country.
This came after Petro had in turn accused US officials of murdering a Colombian citizen and violating his country's sovereignty in one of the multiple strikes that the US military has carried out against alleged drug vessels in the Caribbean since early September.
Experts warn that with the alliance in jeopardy, both Colombia and the US could be at risk of losing out while organized crime groups look set to benefit.
Roots of the US-Colombia alliance
Colombia became one of the main beneficiaries of US aid in the early 2000s, with the money going towards Plan Colombia - a US-funded initiative to combat drug trafficking groups, reduce the flow of drugs to the US, and strengthen the Colombian security forces.
This investment is credited with weakening the Farc guerrilla group, which was at war with the state before officially demobilizing in 2016.
Since then, US assistance has been reduced - and has come under questioning.
Despite Colombia's military successes against armed groups, and its recent years of relative stability and security, some analysts doubt whether Plan Colombia truly resolved the drug problem in the long term.
Cocaine production is currently at record-high levels in Colombia, according to researcher Héctor Galeano from the Institute of Advanced Social and Cultural Studies of Latin America and the Caribbean.
Eroding support
With the help of USAID, Colombia launched several peace and growth projects, especially in poor and conflict-ridden areas. But earlier this year, the Trump administration announced the de facto dismantling of the agency, leading to cancellations of initiatives and the loss of many jobs.
The assistance that does exist funds communications, intelligence, and equipment capabilities in Colombia. Crucially, Trump's administration has now offered cuts amid a rising tide of hostilities.
Trump's recent military campaigns aimed at drug traffickers have cast a long shadow over diplomatic relations, as disagreements about tactics continue to mount.
'Devastating blow'
The deterioration in US-Colombian relations has been described as "a devastating blow" to efforts against armed groups. Analysts express grave concern that the mounting tensions could substantially weaken both countries' security capabilities.
Inconvenient timing
In the midst of these challenges, peaks of violence and drug trafficking persist, heightening the stakes for both leaders' ongoing campaigns. Each country appears to depend on the other for security while facing pressures that threaten to drive them apart fundamentally.
