A longer-term view of world security through the eyes of American defence planners is more than usually important at this time. Since the trauma of the September 2001 terrorist attacks, the Bush administration has adopted an aggressive defence and foreign policy posture that has brushed aside the United Nations - as in the invasion of Iraq - and the multilateral approach to international disputes. That has destabilised the world and raised tensions. Only a few days ago, in his annual State of the Union address, President George W. Bush maintained a destabilising theme by declaring that the United States would 'continue to lead' in the fight against tyranny and terrorism. Therefore defence and foreign policy thinkers the world over will be looking at the four-yearly review of the US Defence Department for clues to the assumptions that will underpin Washington's policy into the future, well beyond the final term of the Bush administration. The Pentagon's view of future threats paints a sobering picture. It should be seen as strengthening the case for international co-operation as the surest path to a safer world, not as an argument for unilateral action by the US. Beijing analysts will not be surprised to read that the Pentagon sees China as the greatest long-term conventional military rival to the US. That assessment is not new - it merely reflects China's phenomenal rise as a global power. However, the world's only superpower does not see China as one of its two top military priorities. These are the defeat of terror networks and preventing the spread of weapons of mass destruction. The quadrennial defence review says the US is engaged in a long war with these threats. It rates them on an upward scale from 'irregular' - terrorism and insurgency - to 'catastrophic', the use of weapons of mass destruction by international terrorist networks or 'rogue' states. Chillingly, the authors say the 'catastrophic' challenge is the most serious threat and the one the US must work hardest to prevent. To counter it, they call for special operations forces that operate anywhere in the world at short notice and in secret, supported by better intelligence and unmanned aircraft for both spying and attacking; stepped up psychological warfare and special units that can locate, track and disable nuclear weapons. China is seen as capable of being either part of the security solution, or part of the problem. The 'choices of countries at the strategic crossroads' - including China, Russia and India - are described as just as important to US security as defeating terrorist networks. The review says US policy envisages China working with other Asian countries to develop regional security structures and deal with common threats, such as terrorism, proliferation and piracy. On the other hand, it acknowledges that China is the power most likely to have the ability to 'field disruptive military technologies' that could offset traditional US military advantages. It sees a need for developing 'stealthy' air and sea forces, including warships that can operate in shallow water and unmanned aircraft. Defence reviews by their nature deal with possible threats and worst-case scenarios and are designed to convince governments to maintain or increase military spending. All powers carry them out. Not all are so transparent about it. An American official admits this one has been shaped by the lessons of September 2001. The darker scenarios it contemplates make it good sense for the US to co-operate with other countries as a basis for combating terrorism. That would make the world safer from both conventional conflict and international terrorism. It ought to prompt Mr Bush to make good his recent pledge of strong backing for the UN by working through it, and to push for further reforms to make it a more effective instrument of international co-operation.