President Xi Jinping's move to officially investigate retired security chief Zhou Yongkang has smashed the biggest unwritten rule in elite Chinese politics - that members of the apex Politburo Standing Committee (PSC) are immune to disciplinary action, say analysts.
What this means going ahead is that no Chinese leader, including Mr Xi himself after his 10-year tenure as the party chief ends in late 2022, can be above the law.
"The message is that there is no such thing as a limit on the level of officials to be investigated and that no one is safe, regardless of their rank," University of Chicago political analyst Yang Dali told The Straits Times.
"This development has really sent shivers down the spines of many top leaders."
Since taking power in November 2012, Mr Xi has launched a relentless anti-corruption campaign that has targeted both "tigers and flies", a phrase referring to both senior and low-ranking officials. More than 30 ministerial-grade officials have been dismissed or charged over violations, mostly corruption offences.
Now that Mr Xi has set a new precedent by publicly going after Mr Zhou, the question on many observers' minds is how much further he will go. Would he, for instance, go after more PSC members or even retired supremos like Mr Jiang Zemin and Mr Hu Jintao?
An online commentary on the state-run People.cn news portal yesterday evening raised eyebrows by noting that the move to investigate the powerful Mr Zhou did not mean the end of the hunt for "tigers".
But analysts say it is unlikely that Mr Xi would risk the party's morale and unity by going after other retired PSC members so soon.
Hong Kong-based political analyst Willy Lam said: "Xi understands that party unity is a paramount factor. He has already established his prestige within less than two years. He doesn't need to risk the party unity by going after another big 'tiger'."
He also discounts the possibility of Mr Xi going after his predecessors and believes he might have struck a political deal with Mr Jiang and retired vice-president Zeng Qinghong, both of whom are Mr Zhou's patrons.
"For other retired leaders, if they stay low and submit to Xi's leadership, it is likely too that they will be safe," said Professor Lam.
Talk of Mr Zhou facing formal disciplinary actions heightened last August after several key subordinates like former assets regulator Jiang Jiemin were investigated.
But Beijing threw up a wall of silence over Mr Zhou's fate, sparking speculation that he would be spared, or that there was fierce resistance from the former security czar and his associates in Sichuan province, as well as the energy and security sectors where he had held leadership positions.
Yesterday's announcement about Mr Zhou could thus be a sign, analysts said, that Mr Xi had forged a consensus among the top Chinese leadership - both current and retired ones - to take action against Mr Zhou.
Investigations that have been ongoing for the past year against Mr Zhou can now proceed through formal channels, said Prof Lam, adding that efforts to halt the process would be unlikely.
Still, there are risks involved for Mr Xi in taking such a bold step, analysts say. For one thing, he has made more enemies who would pounce on him should he make a crucial policy mistake in future. Second, Mr Xi has technically exposed himself to a similar fate in future after he retires.
Noted Prof Lam: "Mr Xi will have to choose a successor who would not do to him what he has done to Mr Zhou."
This article was first published on July 30, 2014.
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