For a while the world has been hearing ominous reports about China extending its military power over the South China Sea and threatening Taiwan. By comparison we hear little about life inside China. But this week Freedom House, an independent think tank in Washington, has published The Battle for China’s Spirit, an extensive and convincing report containing dire news about religious freedom, or the lack of it, under the current regime.

Freedom House’s investigators have concluded that controls over religion in China have been increasing since 2012, seeping into new areas of daily life and triggering growing resistance from believers. At least 100 million people — nearly one-third of estimated believers in China — belong to four religious groups facing high levels of persecution: Protestant Christians, Tibetan Buddhists, Uighur Muslims and Falun Gong.

In one paragraph Freedom House sprinkles a few facts about recent developments: “Tibetan monks are forced to learn reinterpretations of Buddhist doctrine during a ‘patriotic re-education’ session. Dozens of Christians are barred from celebrating Christmas together. A Uighur Muslim farmer is sentenced to nine years in prison for praying in a field. And a 45-year-old father in northeastern China dies in custody days after being detained for practising Falun Gong.”

The Freedom House report says that Falun Gong is still heavily persecuted. Why should it be? It’s a spiritual movement that depends on meditation and constant moral self-searching. When it surfaced in the early 1990s, Chinese officialdom seemed to like it. By the late 1990s, however, the Communist Party saw it as a threat.

When it reached 70 million practitioners it began looking like a force independent of the state. Beijing, like any tyranny, cannot tolerate a competitor. It started a cruel, heartless campaign of propaganda, re-education, imprisonment and torture to eradicate Falun Gong. Hundreds of thousands (maybe a million) practitioners were sent to labour camps where many died (2,000, it is said) and many remain.

The constitution of China provides freedom of religion, with one crucial stipulation: Those taking advantage of this freedom must do so in the course of “normal religious activity.” The government, of course, defines “normal,” which means that congregations worship within state-sanctioned religious organizations in duly registered places of worship.

In the accepted opinion of Beijing, religion is potentially destabilizing, especially in a nation with half a dozen popular religions and many lesser forms of belief. The freedom in the constitution turns out to be the government’s freedom to supervise religion so that it makes as little trouble as possible.

Preaching to potential converts is allowed only in private, or in registered houses of worship. There are many “house churches,” where religious services take place in defiance of occasional harassment.

The Beijing bureau of religious affairs may favour one organization over another for the sake of national unity, even if both share the same beliefs and the same name.

Hui Muslims, for example, are much better treated than Uyghurs, who are also Muslims. The Hui can build mosques and pass on their beliefs to their children through their own schools; after secondary school, the young can study under an imam.

The Uyghurs are not given any such privileges. They are watched constantly by the authorities, and sometimes harassed. Most of them live in China’s western Xinjiang province, where they are 8-million of the province’s 19-million people. Xinjiang is bordered by eight countries including Afghanistan, Pakistan and India. Many Uyghurs hope to separate from China, if necessary through violence.

The Hui, on the other hand, see China as their home and rarely cause trouble. They fit within the state-run Islamic Association of China, which oversees the practice of Islam and regulates the content of sermons and scripture. Hui Muslims employed by the state are allowed to fast during Ramadan, unlike Uyghurs in the same jobs. Hui women can wear veils, a practice discouraged for Uyghur women.

The spectre of mandatory atheism has hung over China since 1949, when the revolution brought to power the Communist Party and its rule that party members must not practice any religion. The Cultural Revolution, from 1966 till 1976, was also a bitter period of suppression for believers. Tradition-hating mobs destroyed thousands of monasteries, churches and mosques. But Deng Xiaoping’s time in power, from 1978 until his retirement in 1989, brought relative tolerance. While opening China to the world economy, Deng relaxed tensions between the state and the various religions.

Under Deng, Christianity experienced a resurgence. By 2011, about 60 million Chinese were said to be practising as Protestants or Catholics. The Catholics are divided between the state-run Chinese Catholic Patriotic Association (CPA) and the Vatican-approved version, with more of the latter than the former. The Patriotic Association’s chairman says its members should “fervently love the socialist motherland.”

Freedom House dates the current wave of oppression from the beginning of Xi Jinping’s first five-year term in November, 2012. (He is expected to be given a second term this autumn.) Xi is sometimes compared to Deng Xiaoping. Like Deng, he knows how to control the party but he’s so far failed to rejuvenate the nation, as he promised to do.

He’s intensified censorship, increasing the paranoia of everyone who disagrees with him or his circle of supporters. And he’s reduced religious freedom, reminding the population every day that there is only one centre of power in China.