Chen Guangcheng's sudden change of heart to leave China after insisting for days he wanted to stay has caught his American supporters off guard. But his reason was simple: His family's safety came first.

Reliant on relatives to be his eyes on the world, Chen and his family share a bond strengthened by years of enforced isolation and a shared fight against vengeful local officials. His son was taken from him two years ago. His daughter has been harassed, his wife beaten, his mother followed by guards as she tilled their fields.

Though the blind activist initially agreed to let China relocate him and his family to the northeastern coastal city of Tianjin, he now says that won't be far enough away from their persecutors in eastern Shandong province to guarantee their safety.

Chen is begging the U.S. to help him go abroad with his wife and two children. He would like his widowed mother to join them.

It's a stunning reversal from a hard-won compromise between China and the United States that saw Chen leave the U.S. Embassy in Beijing where he had taken shelter after a daring nighttime escape from 20 months of abusive house arrest in his rural town.

Just a day ago, Chen's mind seemed made up to remain in China after he was allowed a pair of phone calls with his wife, who had been brought with their children to Beijing via bullet train, U.S. Ambassador Gary Locke said Thursday.

"He spoke with his wife on the phone twice and then we asked him what did he want to do," Locke said. "He jumped up very excited and said, 'Let's go.'"

The alternative, Locke said, was a protracted negotiation, with Chen stuck in the embassy and his family at home and at risk.

"He knew that — and was very aware that he might have to spend many, many years in the embassy," Locke said.

On the way to the hospital, Chen was "emotional, happy about the fact that he was going to be reunited with his family," a U.S. official said Wednesday, speaking on condition of anonymity because of the sensitivity of the issue.

Photos of the reunion released Thursday by the U.S. show Chen in a wheelchair in a bright hospital hallway smiling warmly as he greeted his wife and two children. His 6-year-old daughter, Kesi, wore pigtails and his son of about 10, Kerui, was dressed in a T-shirt and sweat pants. In a second shot, Kerui rested a tentative hand on his father's wheelchair.

The moment marked the first time in two years that the boy had seen his father, diplomats said.

The separation was never by choice.

"They broke up and hurt Chen Guangcheng's family," Chen's lawyer, Li Jinsong, said Thursday. "It was the local government officials who wouldn't let the son go home because he was getting older and was better able to understand things, and what the local officials most feared was that Chen Guangcheng and his family would be able to communicate with the outside world. So, he was left with his maternal grandmother."

A self-taught lawyer, the 40-year-old Chen is best known — and earned the most enmity from local authorities — for his activism exposing abuses in his community related to China's one-child policy, including forced abortions and sterilizations, in a scandal that prompted the central government to punish some local officials.

Chen and his wife, Yuan Weijing, were allowed two children under an exception for disabled people, his supporters say, although Shandong's published guidelines say only a disabled person whose first child is a girl is eligible for a second one. It's not clear if Chen was ever reprimanded or fined for his second child.

Wednesday's reunion was initially painted as a triumph for U.S. diplomacy, but Chen now says his exit from the embassy was a rushed and bittersweet compromise. He said the Chinese government was threatening to send his family back to their rural home, and that U.S. officials pressured him to leave.

"I decided to leave" the embassy, Chen told The Associated Press late Wednesday. "But I felt very frustrated, especially over the threats to my family. They said if I didn't leave, they would take my children and family back to Shandong."

Chen served four years in prison after a 2006 conviction on what his supporters say were charges fabricated by officials in Dongshigu, Chen's home village in Shandong.

Even after he finished serving his term, officials were ruthless in their treatment of the family, beating his wife and mother, and forcing Kerui to leave his parents. Even Kesi was targeted, with guards searching her book bag each day after school.

Chen worried that conditions would be even worse if his family was sent back.

Those concerns were heightened when his wife told him in the hospital that after he escaped last month, seven surveillance cameras were installed inside their home and guards armed with sticks began sleeping there and eating at their table.

"I feel that if my safety could have been ensured I would have wanted to stay," he said. "But now when I look at it, I don't have that kind of hope any more. I now think what I really need is to be with my family and rest."

He added that he was afraid Chinese authorities would think of some excuse to send him back to Shandong despite assurances from the central government that he would be allowed to resettle elsewhere and attend law school, with his tuition and living expenses paid.

Chen's wife has borne much of the retaliatory abuse. In family photos, she looks cheerful, a broad smile gleaming against her bronze farmer's tan, but her ordeal has been long and relentless.

In a video plea taped and posted online last week after his escape, Chen railed against the abuse of his wife.

"They broke into my house, and more than a dozen men pushed my wife to the ground and covered her in a blanket, then beat and kicked her for hours," he said, without specifying when the attack occurred.

In a letter smuggled out of their village last year, Yuan described a Feb. 18 beating that lasted two hours and left her with what she believed were a broken rib and broken brow bone, both still untreated.

She said guards put metal sheets over their windows, confiscated their belongings, denied them medical care and barred them from shopping for food.

She described how a district Communist Party official, Zhang Jian, punched her in the head after she complained about authorities taking the family's property.

In 2007, Yuan's passport and phone were confiscated at the Beijing airport when she tried to fly to the Philippines to accept a Magsaysay Award, Asia's version of the Nobel Prize, on Chen's behalf. She was forcibly returned to Shandong.

In 2009, Yuan's brother-in-law was killed in a car accident. She told a U.S. broadcaster that guards laughed when she pleaded with them to let her visit her grieving relatives.

"Physical pain, I think I can endure that, but the mental pain, I really cannot endure it," Yuan said in a taped telephone interview with New Tang Dynasty TV at the time. "They do not even let me see my sister to comfort her, and my mother. I really feel very sad."

Nor has Chen's extended family escaped the punishment.

His elder brother, Guangfu, was detained last week and is still in custody. Guangfu's adult son, Kegui, used a cleaver to attack local officials who raided his house in the middle of the night after realizing Chen had escaped. He is now a wanted man on the run.

Chen's mother, who lives with the couple, has also been under constant surveillance, with as many as three guards watching her when she works the fields. Chen said in last week's video that guards have beaten her. Around 80 years old, she is believed to still be under house arrest.

"But I don't know what her situation is," he added. "I don't know if she is safe."