TONIGHT'S TV debate between President Bush and John Kerry may determine the outcome of the coming election even though there are still five weeks to polling day. The topic is national security and foreign policy - Iraq, terrorism and America's place in the world. If Mr Kerry cannot use these subjects to claw back some of the lead that Mr Bush appears to have established he will have little chance of emerging as victor in November. In The New York Times yesterday Al Gore, who faced Mr Bush in front of the TV cameras four years ago, contributed an article entitled How to Debate George Bush. It might be thought that Mr Gore is not the person best placed to offer such advice, but then we don't actually know that he lost the last election, do we?

Mr Gore points out that the biggest difference between 2000 and today is that now “President Bush cannot simply make promises. He has a record.” One of the promises he made four years ago was that if he put American troops into combat, “The force must be strong enough so that the mission can be accomplished. And the exit strategy needs to be defnined.” Al Gore urges Mr Kerry to “show voters that today American troops and American taxpayers are shouldering a huge burden with no end in sight because Mr Bush took us to war on false premises and with no plan to win the peace.” There is a huge gap between the picture Mr Bush paints of the current situation in Iraq and the reality on the ground. Mr Kerry's best chance in tonight's debate (CNN 3am local time) is to ram this point home relentlessly.