On Tuesday, masked Taliban gunmen answered Ms. Yousafzai’s courage with bullets, singling out the 14-year-old on a bus filled with terrified schoolchildren, then shooting her in the head and neck. Two other girls were also wounded in the attack. All three survived, but late on Tuesday doctors said that Ms. Yousafzai was in critical condition at a hospital in Peshawar, with a bullet possibly lodged close to her brain.

A Taliban spokesman, Ehsanullah Ehsan, confirmed by phone that Ms. Yousafzai had been the target, calling her crusade for education rights an “obscenity.”

“She has become a symbol of Western culture in the area; she was openly propagating it,” Mr. Ehsan said, adding that if she survived, the militants would certainly try to kill her again. “Let this be a lesson.”

The Taliban’s ability to attack Pakistan’s major cities has waned in the past year. But in rural areas along the Afghan border, the militants have intensified their campaign to silence critics and impose their will.

That Ms. Yousafzai’s voice could be deemed a threat to the Taliban — that they could see a schoolgirl’s death as desirable and justifiable — was seen as evidence of both the militants’ brutality and her courage.

“She symbolizes the brave girls of Swat,” said Samar Minallah, a documentary filmmaker who has worked among Pashtun women. “She knew her voice was important, so she spoke up for the rights of children. Even adults didn’t have a vision like hers.”