THE drive to combat the evil of Al-Qaeda terrorism involves constant vigilance by those countries which have experienced or are in danger of experiencing its scourge. The Kingdom has been in the front line of the fight against the evil of Bin Laden's followers, and no one has played a more central role than Prince Muhammad Bin Naif Bin Abdul Aziz. Thus his appointment as Minister of the Interior by King Abdullah, Custodian of the Two Holy Mosques, is a significant and welcome development. Few people know more about Al-Qaeda and its threat, not simply to Saudi Arabia but to the wider world. Indeed in a perverse admission of the key role that Prince Muhammad has played in crushing terrorist cells within the Kingdom, in 2009, Al-Qaeda tried to assassinate him. The suicide bomber, Abdullah Hassan Al-Asiri, a known Al-Qaeda member, had been allowed to meet Prince Muhammad because he claimed he wished to surrender to him personally. It seemed the encounter would be a repeat of the 2003 surrender of another terrorist, Abdul Rahman Al-Ghamdi to Prince Muhammad. However Al-Asiri had explosives concealed in his body. He died when he blew himself up but Prince Muhammad suffered only minor injuries. It is clear that the attack only increased Prince Muhammad's determination to carry out his counter-terrorism brief as Deputy Interior Minister, where he had been responsible for the successful crackdown on Al-Qaeda's operations in the Kingdom following a spate of terrorist outrages between 2003 and 2007. Indeed during his13 years in the deputy role at the Interior Ministry, he earned international praise and enjoyed widespread respect for the effectiveness with which he carried out his counter-terrorism brief. Saudi Arabia now boasts a formidable intelligence apparatus, which Al-Qaeda has found increasingly hard to avoid. Prince Muhammad also set up special forces units and elite counter-terrorism squads, as well as a tougher and more efficient border security regime. He would be the first to admit that the work of the security and intelligence forces has been assisted significantly by the vigilance of members of the public. Important breakthroughs in the counter-terrorism campaign have been made, because ordinary citizens spotted something unusual in their locality, for instance neighbors who went to a lot of trouble to keep themselves to themselves or who only received visitors late at night. For their part local police stations have become much more alert. After citizens have reported suspicious behavior to the police, the information is immediately passed up the line to the intelligence authorities. Maybe nine times out of ten, there will be nothing to the report. Nevertheless, thanks to the work of Prince Muhammad, systems are in place to evaluate every fresh piece of intelligence in the light of other pieces of information that the security forces already possess. No one would ever claim that the hugely enhanced capabilities of the Kingdom's counter-terrorist campaign will stop another Al-Qaeda attack. To believe that is to be complacent and complacency is the enemy of good security. It is also the friend of the terrorist, who always has the advantage of being able to choose precisely where and when he will strike. The appointment of Prince Muhammad as Minister of the Interior, therefore sends a strong signal, that Saudi Arabia is in no way going to lower its guard. It also makes clear that those terrorists who would do the Kingdom harm are facing an indomitable and highly experienced opponent.