Goofs

In the opening scene in the police car the back projection is shown flipped so that all the store names read backwards. This is probably because the scenes were shot in Britain, who drive on the left, but set in the USA, who drive on the right.

It's a little bit difficult to believe you're in Las Vegas when everyone speaks with a British accent.

The plot would have us believe that all American servicemen are trained to handle and disarm nuclear devices.

If the government was forced to require everyone in America to be quiet so the sonic sensors could find the enemy tunnels , surely they would do so at night.

Once Chinese soldiers were discovered digging tunnels under the United States, so that they could place nuclear bombs in key spots under the country, the US government would have immediately declared war on China.