Updated

President Barack Obama's willingness to engage with America's adversaries comes with promise and peril.

That reality was hammered home by signs of progress in nuclear talks with Iran and a setback in North Korea's provocative rocket launch.

In Colombia, where Obama is attending a summit with Latin American leaders, the president has been confronted by the stubbornly stalled U.S.-Cuba relationship, despite his offer of a "new beginning" with the communist nation.

The convergence of events has focused fresh attention on a foreign policy strategy that puts a premium on keeping the door open for diplomacy, even with countries the U.S. considers "bad actors."