"I think if this was 15 years ago, we would probably have reacted sooner," she said. "There's a real reluctance among American leadership, and myself especially, in committing our troops to another endless war that we don't know when it's going to end."
Born in Thailand to a U.S. Marine Corps veteran and a Thai mother, Duckworth lived in the Southeast Asian country until she was in the third grade.
She can still speak Thai fluently, with only minor mispronunciations in tone.
Duckworth said Mideast countries should take the lead in stopping Syria's humanitarian crisis. "The nations in the Middle East have a responsibility to do something as well. This is their backyard," she said.
Duckworth also met Thursday with Thai Prime Minister Yingluck Shinawatra.
President Barack Obama signaled Wednesday that the U.S. was moving toward a punitive strike of Syria for recent poison gas attacks that allegedly killed hundreds of people.