And what are these "forces hostile to socialism"? Well, the party's experiments with doi moi, or economic renovation, for one. As the report admits, market economics "contains aspects which are contradictory to the nature of socialism".
The cadres assembled in Hanoi have to decide what to do about it, but one look at them tells you how difficult it will be to find the answer. They have no more in common with one another than do the inhabitants of Hanoi, where traditional conical hats and solar topees are still worn, with the silk-clad, mobile phone-wielding people of Ho Chi Minh City. The new Politburo contains an uneasy mixture of Communist warhorses and would-be entrepreneurs: unable to agree on any changes, they have reconfirmed the ruling triumvirate - Do Muoi, the party secretary, President Le Duc Anh, and Vo Van Kiet, the Prime Minister, all over 70 - in their posts.
The foreign businessmen who have poured into Vietnam since the US lifted its embargo believed that the country would be the next Asian economic tiger. Any people hard-working and tough enough to see off the French, the Americans and the Chinese in the space of three decades had to be a good bet, they reasoned. And it is true that the economy has grown rapidly in recent years, raising living standards sharply from their previously abysmal levels. But investment is beginning to tail off, and doubts are growing. Not only is the party's appetite for interference and control undiminished - in a pre-congress campaign against "social poisons", advertisements for many Western products were obliterated or removed - but corruption is endemic.
According to a recent survey carried out by a Hong Kong-based consultancy, proportionally more Vietnamese have their hands in the till than anywhere else in Asia. Next comes China, whose Prime Minister, Li Peng, is a guest at the congress, and where the People's Daily came close to admitting this week that the concentration of power in a few hands made corruption inevitable. Like the Vietnamese, the Chinese know well enough what is wrong. It is just that both Communist regimes reject the obvious solution: giving their citizens the right to choose their own leaders. China has always been simply too big for the centre to maintain absolute control, but in Vietnam it is easier, which in turn makes a decision by the party to loosen its grip all the more agonising to take.
The cartoonist Gary Trudeau has been having fun lately in his Doonesbury strip with a US veteran's inability to come to terms with the present. He returns to Vietnam full of wary defensiveness, only to find the locals completely uninterested in denouncing him - they are too busy wheeling and dealing. But you could make the same jokes about the country's Communist hierarchy, who often seem equally out of sympathy with the desire of ordinary Vietnamese to get on with their lives.
Having fought so many enemies for so long, much of the leadership in Hanoi remains imprisoned by a war mentality. In this sense, they have more in common with the hairy veterans who hang around the Vietnam war memorial in Washington, peddling their conspiracy theories about Americans still being held in jungle PoW camps, than they do with their younger countrymen.