[en] This opening address covers two main areas: first, a snapshot of the continuing threat and the recent changes having been made to the United Kingdom's counterterrorism structures to respond to it; and second, how the United Kingdom is combating nuclear terrorism through a range of measures covering physical security, decreasing vulnerability to attack and increasing resilience. Combating the threat of nuclear terrorism requires an international effort. Radiological and fissile materials are present throughout the world and, as such, it should be secured wherever it is found. All countries are encouraged to continue to enhance security and protection mechanisms for radiological and fissile material; and to develop contingency plans should the worst happen. The United Kingdom has responded to the very serious and real threat by consolidating and strengthening elements of its counterterrorist planning via the creation in May this year of the Office for Security and Counter-Terrorism (OSCT). These changes have been coupled with an unprecedented level of investment to enable the delivery of the United Kingdom counterterrorist strategy - known as CONTEST - through which we aim to (a) stop terrorist attacks; (b) where it cannot be stopped, to mitigate its impact; (c) strengthen our overall protection against terrorist attack; (d) stop people becoming terrorists or supporting violent extremism. In the case of radiological and nuclear terrorism, it is not sufficient merely to prepare for such an attack; one must also devote efforts to preventing such attacks in the first instance by intercepting dangerous materials before they reach their intended target; and by strengthening the protection of vulnerable places and detecting or mitigating any devices before they are placed or activated. As such, in terms of the United Kingdom's efforts on radiological and nuclear terrorism, there are three main strands to this work: physical protection of materials including the global threat reduction programme; decreasing vulnerability to attack; and increasing resilience should an incident occur