New York, United States - From the warzones of Ukraine to Syria and Afghanistan, Washington's foreign policy experts have little to rejoice about. Against this backdrop, US support for peace between Colombia's government and Marxist guerrillas is being lauded as a rare success story this week.

On Thursday, US President Barack Obama will host his Colombian counterpart, Juan Manual Santos, to celebrate a 15-year programme of US military aid in pursuit of a peace deal with the Revolutionary Armed Forces of Colombia (FARC) that is tantalisingly close to fruition.

US officials say the $10bn provided for smashing rebels and narco-gangs via the Plan Colombia scheme since 2000 was money well spent. Helping to resolve Latin America's longest war burnishes the credentials of Washington, which is often chided for destabilising its southern neighbours.

According to Mark Feierstein, a senior director at the White House's National Security Council, the US has helped Colombia to "transform itself" into a "more secure, more prosperous and more peaceful democracy with a vibrant free-market economy".

But finalising the accord could cost as much as getting FARC to the negotiating table. At the request of Santos, Obama will ask Congress to increase its annual assistance to Colombia, from about $300m currently to an unknown sum, perhaps as high as $500m.

Feierstein declined to say how much Obama would request in his forthcoming budget proposal. Roberta Jacobson, a senior state department official, said Plan Colombia 2.0, as it has been dubbed, would aim at state-building in formerly rebel-held areas.

"It will focus on security, including counternarcotics, demobilisation of FARC fighters and demining, expanding the state presence in public institutions," Jacobson said. "And it will focus on justice and assistance for victims of the conflict."

But she warned that the March 23 deadline for signing the accord would likely be pushed back until mid-2016, as the rebels negotiate over such "end-game issues" as handing over their weapons and reintegrating into Colombian society.

Analysts are divided over whether Congress should stump up the cash. Although Colombia has been hit by falling oil prices and the Zika virus, it is richer and more stable than many other states that could use some counter-insurgency dollars.

"The temptation, of course, in Washington, is to declare a success and move on," Eric Farnsworth, the vice president of the Council of the Americas, a think-tank, told Al Jazeera.

But that would be a mistake, he added. If the US takes its eye off the ball, Colombia could quietly descend back into chaos under a weakened FARC, other armed groups and narco-gangs, and present a renewed security challenge in years to come.

An 'imperfect success story'

Shannon O'Neil, a scholar at the Council on Foreign Relations, a think-tank, said politicians would likely open the coffers. Colombia is a "rare country" that enjoys support on both sides of Congress and has given US taxpayers a good return on their investments.

"Colombia will need to invest billions of dollars to reintegrate FARC soldiers, to help millions of Colombians displaced by violence, and to build up Colombia's infrastructure, connecting the country and its people," O'Neil told Al Jazeera.

"The US, along with other nations and international donors, will likely sign on to help fund this process, but in the end it is Colombia that must knit back together its nation."

Former US diplomat Peter DeShazo said 15 years of US support to Colombia only cost about the same as two months' fighting in Afghanistan. The payback - in poverty reduction, less crime and economic growth rates of 4.5 percent from 2002 to 2014 - speak for themselves, he added.

Others are more cautious. Vanda Felbab-Brown, a counterinsurgency expert at the Brookings Institution, a think-tank, describes Plan Colombia as a "very imperfect success story" and says Bogota should shoulder more of the burden.

The Colombians are motivated. Santos, conscious of his legacy, is "actively lobbying" for a Nobel Peace Prize, she said. His government must end the war to secure entry to the Organisation for Economic Co-operation and Development, a club of rich nations.

"Clearly, Colombia deserves US support, but it's also time for Colombia to start paying for itself, far more than has been the case,” Felbab-Brown told Al Jazeera. Bogota should match every dollar provided by Washington, she added.

Confessing to crimes

Others point to the failures of Plan Colombia. Adam Isacson, from the Washington Office on Latin America, highlights corruption and rights abuses in a process that has only resulted in FARC forces shrinking from their peak of about 20,000 personnel to 7,000 today.

"It took 15 years only to reduce the size of the FARC by two-thirds, which still leaves them as one of the biggest and wealthiest insurgencies in the history of Latin America," Isacson told Al Jazeera.

When Plan Colombia was hatched in 1999 by the administrations of Bill Clinton and Andrés Pastrana, then Colombia's president, the country was collapsing under the violence of FARC on the left and violent paramilitary forces on the right, both fuelled by cocaine-trade cash.

The strategy helped cut Colombia's coca crop and helped its government train and equip its security forces so they could regain control over swathes of the country that had been lost to the rebels.

As the number of kidnappings, killings and attacks fell, Colombia's economy picked up and tourists have started returning to visit its once-dangerous colonial towns, coffee plantations and mountain scenery.

After almost four years of talks, negotiators in Cuba have brokered an accord that will see rebels confessing to their crimes to avoid jail time and compensating victims. Those who lay down their weapons will be allowed to participate in local politics.

Many Colombians would rather see the rebels vanquished.

US drug warrants against Colombian commanders

One of the peace deal's loudest critics is former President Alvaro Uribe, whose heavy-handed approach helped force a weakened FARC to the negotiating table. For him, governments should not make concessions to murderous drug traffickers.

"If Santos returns home from Washington with strong support from Republicans and Democrats and a package of support for when the peace deal is concluded, that would strengthen his hand back in Colombia," Farnsworth said.

Santos has other problems. In 2006, US federal prosecutors accused 50 FARC leaders of supplying more than half of the world's cocaine. Santos has asked the US to suspend drug warrants against guerrilla commanders, many of whom are negotiating in Havana.

Feierstein said Colombian officials can make its own "sovereign decisions", about whether to extradite suspects, but that the US "will continue to seek extraditions of those who break US laws so that they can be held accountable in US courts".

"The White House is more likely to grant some form of financial assistance to support the implementation of the accords than to accept President Santos' petition to have the FARC removed from the US list of terrorist organisations and suspend arrest warrants against several FARC leaders," Gustavo Flores-Macias, a scholar at Cornell University, told Al Jazeera.

Follow James Reinl on Twitter: @jamesreinl

Source: Al Jazeera