WHEN A single courageous individual like Liu Xiaobo stands up to an oppressive state like China, the sound that follows is often silence. Mr. Liu was sent into what the Beijing government hopes will be oblivion with an 11-year prison term on charges of subversion for his role in co-authoring and distributing Charter 08, a call for democratic freedoms in China. He won the Nobel Peace Prize in 2010. But his dissent came with a personal price: the anguish and persecution of his family. It, too, has been made to suffer.

Mr. Liu’s wife, Liu Xia, a poet and photographer, has been kept under house arrest for five years although she has been charged with no crime, and the lawless confinement appears to be taking a toll. She was admitted Feb. 18 to a Beijing hospital, suffering from what friends described as a heart ailment and depression. The friends said she had asked for permission to seek medical treatment abroad but was denied.

One can only imagine the pressure and sense of helplessness she must have felt in recent years, not allowed to work or mingle with people, limited to brief visits with her imprisoned husband, talking through plastic dividers. To make matters worse, Chinese authorities brought fraud charges against her brother, Liu Hui, who also was given an 11-year prison sentence, clearly a pressure tactic aimed at her.

Chinese authorities commonly make relatives pay. When lawyer Chen Guangcheng fought the state and eventually escaped China, thugs harassed and beat his family. They, no doubt, intended that reports of the violence would reach Mr. Chen in exile, dampen his spirits and discourage others from following his example.

China has placed Liu Xia in a twilight zone, a sentence for which there can be no appeal, because she has not been charged, but she is surrounded by guards nevertheless. It is a state’s deliberate but undeclared prison sentence, a room without doors. The Soviet Union tried to silence its most famous dissident, Andrei Sakharov, by sending him and his wife, Yelena Bonner, into internal exile in Gorky. The Politburo probably hoped that distance and time would quiet their voices. They did not.

Ms. Bonner’s strength was an inspiration, and one only hopes that Liu Xia can summon the same stoical determination. Journalists and activists have been able to slip past the guards once in a while at her compound, seeing her for only a few minutes at a time. In a video secretly recorded at her apartment in January and released in the West, she read two poems. Her pleas for her basic rights , such as seeing a doctor of her choosing and being allowed to earn a living, have been denied.

The Obama administration likes to put human rights off to the side, something to be mentioned but not allowed to interfere with the important work of bilateral relations. But the “new model of great-power relations” that China envisions cannot succeed as long as its rulers are silencing their own citizens.