On Sunday, the top two candidates for president of one of the United States' closest South American ally nations made it to a runoff election, leaving Colombians to choose on June 15 between the right-of-center incumbent, Juan Manuel Santos, and his far-right challenger, Oscar Ivan Zuluaga.

Zuluaga won a plurality of the vote, with 29.3 percent to Santos' 25.6 percent, but the outcome of the runoff is hardly assured, and the vote has ramifications far beyond political ideology.

Santos took the bold step in 2012 of initiating peace talks with the Revolutionary Armed Forces of Colombia (FARC), the world's oldest guerrilla army and a major player in the drug-fueled violence that has plagued the nation for half a century.

While the talks, held in Havana, have moved slowly, the Colombian government and the FARC have managed to reach unprecedented agreements on a number of points that could lead to the most substantive peace agreement in decades.

Aside from offering a huge boost to the already growing Colombian economy and dealing a major blow to one of the largest sources of illegal drugs entering the United States, disbanding the FARC would further cripple Venezuelan President Nicolas Maduro, who along with his predecessor Hugo Chavez has tacitly offered financial support and shelter to the guerrilla army primarily on the grounds of its Marxist ideology.

Zuluaga, the candidate backed by controversial former president Alvaro Uribe, has stated that he would immediately end the peace negotiations and return to Uribe's policy of brute military force against the FARC.

Though the connection has never legally been proven, Uribe is widely viewed as having been instrumental in the rise of paramilitary death squads that decimated the FARC but also committed widespread human rights violations and quickly became involved in the drug trade themselves.

Several of Uribe's closest political allies received prison sentences for their involvement in paramilitary abuses, though the former president has so far avoided trial.

His administration was also marred by the notorious "false positives" scandal that reportedly involved executing innocent teenagers often from poorer neighborhoods, dressing them in FARC uniforms and passing off their deaths as proof of military progress against the guerrilla organization. Uribe has denied any involvement in or knowledge of the strategy, and allowed cases to be tried in civilian court to help ensure impartial trials.

Despite all of this, Uribe has remained a formidable political force, riding a wave of electoral success that swept himself and his party - of which president Santos is a member - to a Senate plurality in March.

Uribe backed Santos, his former defense minister, during Santos' successful 2010 presidential campaign, but threw his support behind Zuluaga in 2014 after a falling-out over the peace talks, which Uribe has harshly criticized as pandering to a terrorist organization.

However, Santos can hardly be accused of being soft on the FARC. He has maintained military campaigns against the guerrilla organization even during the peace negotiations, and many analysts agree that the FARC would never have entered the talks in the first place had they not felt that their military defeat was imminent.

But that is no justification for scrapping Colombia's best chance for lasting peace in decades. The talks are unlikely to solve the nation's stubborn problem of drug violence, and many threats to stability will remain, but an agreement would unquestionably be a step in the right direction for a country desperate to shift headlines away from cocaine and kidnapping to its explosive economy and burgeoning creative renaissance.

A continuation of Santos' moderate presidency would preserve a strong ideological and economic ally in a strategic location, while continuing to open Latin America to foreign investment and trade.

Furthermore, few forces threaten autocratic regimes like Venezuela's more than the stark contrast between violence and economic despair at home and peace and booming prosperity just across the border.

Ed Buckley, a Post and Courier news staffer, is a former associate editor with The City Paper Bogotá, an English-language newspaper based in Colombia's capital.