Team America: World Police, a satire on the war on terror by the makers of South Park, opens today in the US, but Trey Parker and Matt Stone's flick, featuring Thunderbirds-style puppets, has already spread mirth throughout the land.

The boys were in danger of receiving a commercially ruinous NC-17 certificate for a scene in which two marionettes indulge in an intimate act that the last president of the Union famously refused to define as sexual intercourse. "Our characters are made of wood and have no genitalia," producer Scott Rudin said. "If the puppets did to each other what we show them doing, all they'd get is splinters."

Trey Parker went to on to point out that, bizarrely, the authorities had no problem with them setting fire to a Tim Robbins doll or throwing a wooden Susan Sarandon off a high building. Following cuts, Team America received an R certificate.

So far as we can judge, nothing ghastly befalls Sean Penn in the movie, but the actor, suffering a sense-of-humour bypass, has sent the equal-opportunity satirists an angry note objecting to a scene ridiculing P Diddy's Vote or Die campaign. Oh, please.