BOGOTA, Colombia—Ingrid Betancourt sat handcuffed in a helicopter with 14 other hostages, angry and frustrated at what she thought was just another maneuver by her rebel captors. Then she noticed something odd:

“Suddenly I saw the commander, who for so many years ... was so cruel, so humiliating, so despotic, I saw him on the floor, naked, blindfolded,” she recalled Wednesday. “The chief of the operation said, ’We’re the national army. You’re free.’ “

Colombian spies had tricked leftist rebels into handing over the kidnapped former presidential candidate and three U.S. military contractors Wednesday in a daring helicopter rescue so successful that not a single shot was fired.

“The helicopter almost fell from the sky because we were jumping up and down, yelling, crying, hugging one another,” Betancourt, captive for six years, said. “We couldn’t believe it.”

Eleven Colombian police and soldiers were also freed in the rescue, the most serious blow ever dealt to the 44-year-old Revolutionary Armed Forces of Colombia, which considered the four hostages their most valuable bargaining chips.

The Americans—Marc Gonsalves, Thomas Howes and Keith Stansell—were flown directly to the United States to reunite with their families and undergo tests and treatment in San Antonio, Texas.

Nowhere in the world have American hostages currently in captivity been held longer, according to the U.S. Embassy in Bogota.