So she rebranded her campaign. Instead of describing it as “a project on the secret U.S. bombing in Laos,” she called its mission “history, healing, hope.”

She brought over a young amputee from Laos who was born after the war and who delivered a message of humanitarian need free from politics.

She targeted members of Congress with large Laotian populations in their districts. In 2010, she testified before Congress, urging more funding for bomb clearance and assistance for victims.

And the attitudes of Lao-Americans have changed in recent years as more have returned to Laos, Ms. Channapha said. “As their own personal relationship with the country was evolving and changing, so did their opinion about what we were doing,” she said. “They were starting to understand that it wasn’t about taking sides.”

Mr. Kingphet, the ordnance clearance manager, praises Ms. Channapha’s efforts, but he said the United States should do more. Many Americans are still unaware of the war in Laos, he said.

“Some Americans come here and they are shocked at how many bombs were dropped,” he said.

The United States provided roughly 30 percent of the $40 million that charities and governments — including those of Australia, Ireland, Japan, Norway and Switzerland — are contributing to clearance efforts this year. But even with a surge of money, it will be decades before all the unexploded bombs are removed from the Laotian countryside. In the meantime, officials are traveling to remote corners of the impoverished country and urging caution.

Houmphanh Chanthavong, a government official who was among the group visiting Houaykhay village, told residents of the painstaking process to remove ordnance from the ground, the metal detectors and the clearance experts who delicately dig for them.

“We keep on digging,” he said, “and we keep on finding more.”