It has been almost four years since US President George W. Bush declared a global 'war on terror'. But as last week's London bombings show, terrorists are far from defeated. From Bali to Madrid, fanatical followers of the Islamic extremist group al-Qaeda are believed to have killed more people since the September 11, 2001, attacks in America than they had in all the preceding years. Mr Bush's anti-terrorism strategy is not working. He must rethink his current approach and devise a more effective plan that is less reliant on raw military power and more on sophisticated intelligence and police work. Alas, Mr Bush does not seem inclined to do so any time soon. In his Monday speech before a group of FBI recruits and marines in Virginia, he said the best way to crush terrorists was to wage an offensive war to keep them on the run. He added that the US military mission in Iraq was a 'central front' in the war on terror. His message was stubbornly clear: stay the course. Sticking to his guns in this case, however, seems more like denial than a sign of strong leadership. For months, it has been obvious that the pre-emptive invasion of Iraq on the trumped-up threat of Saddam Hussein's weapons of mass destruction has not made the world any safer from terrorist threats. On the contrary, US military excesses in Iraq have become a rallying cause of radical Muslims everywhere and the best recruitment propaganda for potential Islamic terrorists. The vast deserts of Iraq are not big enough to bog down all the angry militants and prevent extremists from launching battles in other lands, as US officials like to claim. National security experts tell us that fighting a global cabal of stateless terrorists is fundamentally different from waging a conventional war. The enemy does not wear an easily recognisable uniform and no amount of military firepower can wipe out an adversary who might be your neighbour or co-worker. Osama bin Laden may be the supreme commander of al-Qaeda, but many of its local cells operate without his direct leadership. Countering such an 'asymmetric threat' requires less an army of tanks and missiles but more a comprehensive scheme of public-awareness campaigns, round-the-clock police vigilance and maximally empowered intelligence services. Yet Mr Bush's opponents in Congress say he is spending more money on Iraq in a month than he does on frontline homeland security in a year. True, no perfect security exists against acts of terror. That is why the only long-term solution is to remove the root causes of terrorism. Mr Bush has rightly identified a stable Iraq and the spread of freedom and democracy in the Middle East as crucial elements in this effort. But to achieve success, he needs to show more patience and wisdom than he has so far.