If you want to take a pop at Corporate America there’s no easier target than the monster that is Wal-Mart – the world’s largest supermarket chain. Its gargantuan size and total dominance of grocery shopping in the United States, not to mention its many subsidiaries abroad including Asda here in the UK, make it the epitome of rampant capitalism and globalism gone crazy.

Greenwald’s documentary does not pull its punches. There is no-one there to put the case for Wal-Mart. Greenwald starts the film with clips from the Wal-Mart annual shareholder meeting. It’s more like a religious rally. The point is clear: all that matters to Wal-Mart is that they deliver more value to shareholders through bigger profit margins. And why not? Greenwald offers plenty of reasons. It does little to help America’s balance of payments with China. Wal-Mart’s aggressive costcutting has seen a huge increase of imports of its products from China. Any mention of China these days is enough to conjure up the image of appalling working conditions and destruction of local industry and Greenwald is happy to play on this.

Greenwald attacks Wal-Mart’s ability to distort the market with its near monopolistic position. Local politicians, faced with the choice of accepting a proposal for a new Wal-Mart store in their town or seeing it sited just outside the town’s borders, cave in and allow Wal-Mart in. As a result local shops are forced to close. Greenwald uses the example of a typical family business, a large DIY store in a small American town, that eventually has to close because Wal-Mart is creaming off its business. Even the value of the large shop premises is driven down because Wal-Mart is such a dominant competitor, making it impossible to sell at a decent price, if at all. We are shown towns where the shops have all been deserted because of the opening up of a new Wal-Mart store nearby. It’s as if a neutron bomb had hit them. The film offers us the two opposing sides of the American dream. Mom & Pop businesses which grow slowly and serve their local communities; and Wal-Mart. Of course, that’s also how Wal-Mart started but Greenwald is also quick to point out how little the founding family members of Wal-Mart have ever donated to charity, certainly in comparison with Bill Gates. It’s grotesquely shocking how little these billionaires are prepared to share.

The director interviews a whole string of ex Wal-Mart employees and gives us a horrific insight into their employment practices. The intense pressure on managers to cut costs whatever the impact on staff, the oppressive monitoring of any attempts by staff to try and unionise the workforce and the encouragement of staff onto Medicaid by offering company health insurance only at an exorbitant premium. This contrasts with Wal-Mart’s subsidiary in Germany where unions are strong. There the company had to recognise the unions and has to give its employees 36 days holiday a year. The question being, if unions are acceptable in Germany, why not in the US?

But it’s not all doom and gloom. Greenwald also gives examples of where citizens groups have successfully campaigned against Wal-Mart and stopped them from opening up a new store. The networking and campaigning skills and sheer determination of these people is admirable. It mirrors recent campaigns against Tesco in the UK. The film also refers to the current attempt by Asda to set up a major new store in West Ham on the site of the famous Queen Street Market, much to the chagrin of the local traders.

Following hot on the heels of Morgan Spurlock’s Super Size Me, this is another hard-hitting documentary exposing the pernicious side of massive American companies. Yet in doing so it does not attempt a general critique of capitalism but is very tightly focused on the aggressive tactics of one particular company. You don’t have to be an anti-globalisation campaigner to feel outraged by what the film shows. It’s a plea for a little humanity amidst the headlong rush for ever cheaper food for already rich consumers and greater profits for already rich shareholders.

The film is not as personal or entertaining as Super Size Me but is, if anything, more provocative. Greenwald’s other recent work includes his critique of Fox News, Outfoxed: Rupert Murdoch’s War on Journalism and Uncovered: The War on Iraq (both released 2004) so it would be safe to say that he’s not too popular with the right wing in America. Wal-Mart has already launched its own rebuttals to many of the points raised by the film. But this film makes it abundantly clear that for all the talk of competition and free trade the corporate giants are more than ready to make up their own rules for the game.

Wal-Mart: The High Cost of Low Price is currently showing in the UK.