Few observers will be surprised to hear that radical Islamists will, this year and beyond, keep trying to carry out terrorist operations in Britain. But the form of the next attack may be very different from what security services have been preparing for. That was demonstrated by the recent revelations of an alleged plot to kidnap - and broadcast the killing of - a Muslim British serviceman. Terrorists are always adapting and innovating; the authorities constantly playing catch-up. It's now a gravely serious game of cat and mouse. Much has been made in the media of the similarity between that alleged plot and the brutal tactics we have become so accustomed to in Iraq. Yet, if the leaked details about the attack prove to be accurate, it could have had unprecedented psychological, poli- tical and social effects. Many kidnappings and killings of western hostages have been carried out on terrorists' home soil by insurgents in war-torn Iraq. But the recent plot apparently involved a kidnapping and killing on western home soil. It would thus have represented a new level of horror for the public, and a new dimension of threat for western security agencies to adapt to. Constant adaptation and change have become the key characteristics of Islamist terrorism, in its quest to become and remain as elusive as the proverbial needle in the haystack. Just when authorities believe they have a grip on the terrorists' identities and plans, the nature of both change. This ever-altering approach to organisation and tactics has emerged along with a profound understanding of the power of the western media - and the potential to use it as a tactical and psychological weapon. By ensuring that their attacks and activities grab headlines, terrorists amplify their operational strength, generating and manipulating public debate. This is such a potent weapon in the terrorist arsenal: it has the desired effect even when such plots are discovered. Even details of failed plots dom- inate our headlines, increase public fear and anxiety, and ensure radical Islamist terrorism remains at the forefront of our thoughts. The recent scheme shows us once again how the target of radical Islamists is the hearts and minds of Muslims - especially integrated Mus- lims living in the west - as much as the west itself. It sends a crystal-clear message to Muslim communities: don't join the armies or agencies of 'enemy' states, because that will make you a traitor to be sought out and targeted. The radicals want to drive a wedge between Muslims and society at large, forcing people to choose between loyalty to their faith or their country. Many Muslims are integrated members of western societies with which they are proud to be associated. They see no contradiction between this and their strong religious identity, and that is exactly what the terrorists want to attack and undermine. In the coming months, security agencies will be preoccupied not only with how to identify such plots before they are carried out. Just as importantly, they will be trying to learn how to predict the new forms that terrorist attacks may take. Such kidnappings in the west were not anticipated, just as the use of commercial aircraft as missiles in the 9/11 attacks wasn't foreseen. What will terrorists do next? Is there any way to predict it? The likely answer to the second question is 'no'. So identifying future terrorists - and thereby learning what they are planning - will remain the key activity of counterterrorist agencies. The terrorists, meanwhile, will continue to seek new ways to surprise us - and thus horrify and appal us - once more. This cat-and-mouse game will continue for quite some time yet. Hagai Segal, a terrorism and Middle-East specialist, lectures at New York University in London