“WITH you in charge, I am at ease,” Mao Zedong is supposed to have told his successor, Hua Guofeng. It proved a disastrous choice. Mr Hua lasted a couple of years before being toppled in 1978. A decade later succession plans once again unravelled spectacularly, against a backdrop of pro-democracy unrest. Only once, eight years ago, has China's Communist Party managed a smooth transfer of power—to Hu Jintao. Now a new transition is under way. The world should be nervous about it for two reasons: the unknown character of China's next leader; and the brittle nature of a regime that is far less monolithic and assured than many foreigners assume.

The man ordained to take over Mr Hu's twin roles as party chief in 2012 and president the following year is hardly a household name. On October 18th Vice-President Xi Jinping was given a new job as vice-chairman of China's Central Military Commission, which Mr Hu heads. This is a position for leaders-in-waiting. The portly son of one of Communist China's founders, little known to the outside world until a few years ago, Mr Xi is preparing to take the helm of a country with the world's second-biggest economy and its biggest armed forces—and which is in the midst of wrenching social change.

Quite how he has risen so high in a party that, for all its growing engagement with the world, remains deeply secretive, is unclear. Mr Xi's appointment was eerily similar to the recent anointing of Kim Jong Un in North Korea: he too was made vice-chairman of a military commission after a closed-door party conclave, without public explanation. China's leaders at least offered a sentence on Mr Xi's appointment, albeit at the end of an arid 4,600-character communiqué after the fifth party congress (see article).

On the positive side, Mr Xi has held some big posts in the most economically dynamic and globally integrated parts of the country: the coastal provinces of Fujian and Zhejiang as well as, briefly, Shanghai. He is a relatively cosmopolitan figure. His wife is a popular singer. But it is impossible to assess how well qualified he is to run the country or how assured his succession is. On the face of it, one engineer whose father was denounced during the Cultural Revolution is handing over to another. But Mr Xi is a relative newcomer to the inner circle; he has not served as long as Mr Hu had in 2002. There are plenty in the party who resent the rise to power of well-connected “princelings” like Mr Xi. A two-year transition will be a test.

All this one day will be yours

All the same, it is the immensity of the task, not the obscurity of the man, that should make the world nervous. For all their outward expressions of unity, there are signs of disagreement among Chinese leaders over what the country's priorities should be—both on the economy and on political reform.

The economy is sprinting along by Western standards, but China faces a hard adjustment to wean itself off excessive investment and exports in favour of more reliance on consumption. The communiqué unveiled guidelines for a new five-year economic plan (see article). This calls for a more sustainable pace of growth, with wage-earners getting a bigger share of the national income. This would be good for China and the world, helping to narrow the trade surplus that annoys America so much. But the change will not be painless. Exporters fear business will suffer if wages soar or the yuan rises fast. Powerful state-owned enterprises, used to cheap credit, land and energy, will resist threats to these privileges.

As for political reform, Chinese leaders have talked about democracy for the past 30 years, but done little. Rapid growth and the spread of the internet and mobile phones have enabled Chinese citizens to communicate, vent their grievances and pursue their dreams more freely than before, so long as they do not attack the party. But some are now demanding more say in how the country is run. In the past few weeks China's more liberal newspapers have enthused about calls by the prime minister, Wen Jiabao, for “political reform”. Conservative newspapers have censored them.

There is next to no chance of the cautious Mr Hu bringing in big reforms before he steps down. This week's communiqué hailed the “political advantages of China's socialist system” and mentioned political reform only briefly, saying—as Chinese leaders so often do—that it will require “vigorous yet steady” effort. Even Mr Wen, who will step down at the same time as Mr Hu, has wanted to move at glacial speed.

Expect paranoia and you may be pleasantly surprised

Might Mr Xi speed things up? There is no shortage of conservatives arguing for caution, but there is also a pragmatic argument for change: China's economic gains could be jeopardised by a failure to loosen the party's hold. Explosions of public discontent, fuelled by resentment of government callousness towards ordinary citizens, are becoming increasingly common in villages, towns and cities across the country. The (admittedly patchy) official data show a more than tenfold increase in the annual number of large protests and disturbances since 1993, with more than 90,000 cases reported in each of the past four years. In the past China's leaders have relied on growth to secure social stability. If and when a more serious slowdown strikes, popular grumbles could increase.

The right path for Mr Xi should be clear: relax the party's grip on dissent, lift its shroud of secrecy and make vital economic reforms. But the rest of the world would be unwise to assume that reason will prevail. In times of uncertainty, the regime is wont to appeal to nationalist sentiment. Large anti-Japanese protests erupted during the latest party meeting. America and the West have also been subjected to tongue-lashings. The party meeting called on officials to strengthen “the country's comprehensive national power”.

Too many Westerners, including those urging trade sanctions over the yuan, assume that they are dealing with a self-confident, rational power that has come of age. Think instead of a paranoid, introspective imperial court, already struggling to keep up with its subjects and now embarking on a slightly awkward succession—and you may be less disappointed.