LIKE so much else under Heaven, repression in China has often seemed to go in cycles. Every now and then it has suited the country's leaders to relax their steely grip on the country and allow a modicum of political liberty.

Freer criticism in the media has helped give the party a veneer of credibility. Lip-service to the law and due process has won plaudits overseas and boosted the economy at home. So a thaw would set in for a while, a “Beijing spring”. A freeze would always follow. But, until lately, in each new cycle the springs were seeming warmer and the freezes not quite so harsh. When the country was starting to liberalise, Westerners justified doing business with China on just such grounds. More economic openness would surely lead to more openness of other kinds.

The latest freeze casts this widespread hope into doubt, for three reasons. The first is the scale of the crackdown. Ai Weiwei, China's best-known artist and dissident, who was detained at Beijing airport on April 3rd, is only the most notable figure to be caught by it. Calls on the internet for a “jasmine revolution” have prompted armed police and plain-clothes goons to descend in huge numbers on public places to stop people from “strolling”, as a veiled form of protest.

Baby, it's cold outside

Dozens have been detained and now face criminal charges in relation to these inchoate calls. Others have faced different kinds of harassment, including beatings and house arrest. But the freeze runs deeper. Since February some of the country's top defence lawyers have vanished. Activists for villagers' rights and the environment have faced repression. Bloggers have been rounded up. Members of a big underground (ie, non-state) church in Beijing, stopped from meeting in their usual building, were arrested as they tried to worship outside.

A second reason for doubt is the duration of the crackdown. With hindsight, it began after Tibetan riots in 2008 drew a harsh response. Since then, two events, the Beijing Olympics later that year and the Shanghai World Expo of 2010, might have served as coming-out parties for a rising China. They offered the regime the chance to show the world a more confident face. Yet both were accompanied by harsh treatment of anyone deemed likely to embarrass the government. Tens of thousands of unwashed migrant workers were forced out of Beijing for lowering the tone. Outspoken activists were kept out of sight.

Even natural disasters have triggered repression. Mr Ai's first serious run-in with the authorities came when he attempted to account for all the schoolchildren killed during the Sichuan earthquake in 2008, many as a result of corrupt building practices. Taking in all its manifestations, which include tightened internet censorship and a stifling of public debate, the latest crackdown on political dissent certainly constitutes the worst since Tiananmen Square in 1989 and its aftermath.

A third reason to doubt the notion of gradual warming lies in the method of repression. Even the post-Tiananmen crackdown had a semblance of due process. Now such pretence is out of the window. People are picked up under arbitrary detention rules and then made to disappear. Mr Ai has not been heard of since being bundled away. Violence is part of the mix. Mr Ai needed brain surgery in 2009 after being beaten up by goons. Foreign journalists are being harassed on a scale unseen since Tiananmen Square. Vaguely defined “state security” is used as a reason to round people up. For perceived “troublemakers” such as Mr Ai, the government says, “no law can protect them.”

Western observers tend to describe the crackdown as a massive overreaction to perceived threats, but it may well be that China's rulers know better. True, no seething mass stands ready to overthrow the regime. But in a vast country, many aggrieved people, from dispossessed villagers through unemployed graduates to angry bloggers, resent the state. The government is quite capable of handling each of these groups separately. But were those with grievances ever to coalesce, especially if the growth slows—as it will sooner rather than later (see article)—they would represent a potent force.

The view from Beijing, thus, is different to the view from abroad. Whereas the outside world regards China's rulers as all-powerful, the rulers themselves detect threats at every turn. The roots of this repression lie not in the leaders' overweening confidence but in their nervousness. Their response to threats is to threaten others.

Imminent political change may also play a part. Next year a crucial party congress will anoint a new generation of leaders, led by Xi Jinping, now the country's vice-president, to take over the running of the country. Repression is the job of China's powerful “security state”—the regular and secret police. Sensing rudderlessness at the top, it may be particularly inclined to flex its muscles now.

The fear of hanging separately

Many of China's new leaders come from the “princeling” class, an aristocracy of families with revolutionary credentials from the days of Mao Zedong (see article). Some have lucrative positions which give them a financial interest in tighter party control over both the economy and society. Others use their ideological pedigrees to advocate a neo-Maoist approach, which includes scant regard for the law. There is plenty of resentment within the system at the growing power of this aristocracy, and repression can be used to defang opposition. A nastier China is the result.

In the short term at least, these troubling developments undermine the comforting idea that economic openness necessarily leads to the political sort. All the more reason, then, for the West to hold China to account. America and the European Union are right strongly to condemn Mr Ai's detention, though it would have been better had they taken a stand sooner. Speaking out might just help constrain the regime's behaviour. It will certainly give succour to those in China working bravely to create a better future.