China has shifted its clampdown on dissent up a gear with the detention of a world-renowned artist, Ai Weiwei, revealing a government at once insecure about its grip on power and yet unruffled by Western criticism of its heavy-handed rule. It is a paradoxical mix of anxiety and disdain that will define the country's politics as a leadership handover presses closer. The burst of detentions and arrests of dissidents, human rights lawyers and now Ai - an outspoken artist with a high profile abroad - shows just how far the ruling Communist Party fears the nation's economic boom will not inoculate it from internal threats. The government says Ai is suspected of economic crimes, a charge his family says is a pretext for stifling his activism. Ai's arrest drew swift condemnation from Western capitals and has raised the prospect of months of diplomatic friction but, hunkering down for a long offensive to stifle opponents at home, Beijing appears emboldened to ignore critics abroad. The next big test of how far Beijing could push will be whether Ai or well-known detained rights lawyers, such as Teng Biao, are formally arrested, bringing trials and convictions by Party-run courts. “Before they were killing the chickens to scare the monkeys, but with Ai Weiwei, they're killing a monkey, and that's a bigger deal,” said Liu Suli, a bookstore owner in Beijing who was jailed after the 1989 crackdown on pro-democracy protests. “Killing chickens to scare monkeys” is a Chinese saying used to describe punishing a smaller foe to deter bigger ones. “Ai Weiwei has many fans here and abroad, so by going after him, you can scare all his fans, all the chickens,” said Liu, a seasoned observer of the Chinese political cycle whose All Sages bookstore is a meeting point for liberal thinkers. “It's also killing a monkey to scare the other big monkeys”, he added, referring to other well-known dissidents. Plenty of experienced observers are dismayed by the extent of the crackdown, even given Party worries that anti-authoritarian unrest in the Middle East could infect China. Mass turmoil seems a distant threat. China's security forces are swimming in cash and bristle with advanced technology to nip unrest in the bud. Beijing has economic headaches, but they reflect a problem that most governments yearn for - too rapid growth. But even after the Middle Eastern upheavals have died down, China's tight grip is unlikely to loosen much as the Party readies a leadership handover from 2012 that is likely to see President Hu Jintao stand aside for Xi Jinping, now vice president. Speeches and documents on Chinese government websites betray official anxiety that Western-backed threats to stability are becoming increasingly entrenched. That will make for economic, social and political policies that prize control above all. “Many in Beijing are positioning themselves now for the upcoming leadership changes in 2012 and can't afford to be seen as ‘soft' or as taking any chances,” said Fei-Ling Wang, a professor at the Georgia Institute of Technology in the United States who specializes in Chinese politics. Beijing intellectuals are divided over whether Xi's succession will bring some relaxation, but most see relative moderation rather than a springtime of liberalization. Xi is a more personable figure than Hu, but so far has been cautious and conformist. “We thought there'd be a freeze (before the succession) but it came early,” said Liu, the bookstore owner. “The prince and the emperor would both worry about who'd shoulder responsibility for chaos, especially the prince,” he said, referring to Xi and Hu. “There a sense that the economic situation doesn't rule out crisis, so best do everything to strangle it in the cradle,” he said, giving his view of leaders' thinking. ‘Hostile forces' China's curious cocktail of fear and swagger has been spelt out most starkly in speeches by local officials, who pay less heed to diplomatic scruples about openly accusing Western governments of trying to topple the Communist Party. A directive from Yuzhong County in the northwestern province of Gansu declared, for example: “Since the abrupt changes in Tunisia and Egypt, Western forces hostile to China have been itching to do something and do their utmost to stir up a fuss.” Dozens of such warnings about “hostile forces at home and abroad” threatening the Party and stability can be found on local government websites. Senior officials have been more guarded about voicing such fears, but they have been clear enough. President Hu and Vice President Xi both gave keynote speeches to a leaders' meeting in February demanding new ways to keep control over Chinese society, including its internet-using population of 457 million. The warnings of imminent political threats have rippled down the state hierarchy and have pushed police and state security to sweep up dozens, if not hundreds, of dissidents, rights advocates and ordinary protesters in secretive or extra-judicial detention, paying little heed to conventional legal rules. “This deeply worrisome crackdown seems to me to reflect a strange mixture of confidence and insecurity,” said Jeffrey Wasserstrom, a professor at the University of California, Irvine, who specializes in protests in modern Chinese history.