Missile Defence (MD) should not be seen as merely the passive protection of US citizens from an aggressive enemy or terrorist action – but as a means of transferring the theatre of war into the space environment. Nor is it just a policy of the Republicans under President Bush. The origin of the term ‘Star Wars’ is usually associated with Ronald Reagan’s famous 1983 speech but the concept dates back to the days of the ‘space race’ at the height of the Cold War and has been supported and funded by all US governments since then.

The US became convinced of the requirement for space control and dominance during the Gulf war in 1991 and the conflicts in Kosovo in 1999, Afghanistan in 2001 and Iraq in 2003, demonstrated that the use of space technology for reconnaissance, surveillance, communications and battle management gives an overwhelming military advantage. The incentive is: who rules space, also rules the Earth.

The US Space Command’s 1996 documents "Vision for 2020" and "Long Range Plan" recognise the widening division between the global economic ‘haves’ and ‘have-nots’ and introduce the doctrine of "full spectrum dominance" (the military dominance of the land, sea, air, space and information) to protect the interests of the ‘haves’. In order to protect "US interests and investments" on a world-wide scale, Space Command claims it must maintain supremacy in, and deny others access to, space. These intentions are also clearly stated in US policy documents such as Donald Rumsfeld’s 2001 Space Commission report which highlights the need to dominate all aspects of space and to defend it against a possible "Space Pearl Harbor". The tragedy of September 11, 2001 and the increasing emphasis on possible missile threats from "rogue states" and terrorists, have given the American right a huge boost in their campaign to develop aggressive space-based systems as a way of exerting full control over world affairs. This so-called "Revolution in Military Affairs" is firmly rooted in the ‘Project for the New American Century (PNAC)’.

There are no weapons stationed in space, yet, but the rationale offered by the military in support of the development of a war fighting capability in space is their increasing reliance on vulnerable satellite systems. The US already has a range of programmes to develop weapons such as space-based lasers (to target space and ground based objects) and the military space plane (which will replace the aging space shuttle fleet and could be used to destroy satellites). Although illegal under the Outer Space Treaty, the stationing of nuclear weapons in space is also being actively considered.

The US move to space based weapons as a way of exerting a military presence on Earth could mean fewer (American) casualties, quicker response times and less need for foreign bases from which to launch attacks. Also, although ‘allies’ are always welcome to help them legitimise their actions, the US is clearly quite prepared to act unilaterally. In fact James Roche, the USAF Secretary, has already made it clear that America's allies would have "no veto power" over projects that are designed to give the US military control of space.

Where the US leads, others will follow. Russia, China and India have already made it clear that they will not let a US war fighting capability in space go unchallenged. Although the Bush Administration has shown a willingness to ignore or withdraw from international treaties, it is imperative that a Prevention of an Arms Race in Outer Space (PAROS) treaty becomes the subject of a high profile international debate and that new agreements are arrived at before we enter what would almost certainly be the final battlefield.

Dave Webb is Professor of Engineering at Leeds Metropolitan University