Q & A: Son of Star Wars
Friday, 13 July, 2001
The US Administration under President George W. Bush favours the development of an anti-missile defence system, dubbed by some "the son of Star Wars". BBC News Online looks at how such a system might work, and what the international implications would be:
What is the plan?
The plan, originally called the National Missile Defence programme, is to develop and deploy a defensive screen for the whole of the US, which would have the ability to track and destroy incoming ballistic missiles.
It has been nicknamed son of Star Wars after the original Strategic Defence Initiative - or Star Wars - of President Reagan, although the new plan is not nearly as complex or extensive.
Washington is hoping that radar and communication systems, some based in the UK and Greenland - in combination with satellites in space - would provide early warnings of an attack.
The incoming missiles would then be destroyed by sophisticated interceptors based in the United States.
In an effort to win over wavering allies, the Bush team has now dropped the "national" from the missile defence project.
They are now proposing a multi-national defence system covering the territory of as many countries that want to sign on.
But the bigger the area to be defended, the greater the technical challenge ahead.
Where does the threat come from?
The system is primarily being designed to defend the US from small-scale attacks by countries such as North Korea, Iran, or rogue states elsewhere in the world.
US defence planners are alarmed by the missile programmes of some of these countries, which are not only increasing their range, but could also be developing chemical or nuclear warheads.
The US insists the defence system is not intended for Russia, and that Moscow should recognise that it also faces the threat of nuclear attack from rogue nuclear states.
How accurate would it be?
The system is faced with the challenge of destroying several incoming missiles, without debris falling on the intended target. That requires early warning, accuracy, and multiple shots.
The technologies are still highly risky, and several tests have already failed or been delayed.
The system would also not be able to defend the country against a sustained ballistic missile attack.
How does it differ from the original SDI?
The original Strategic Defence Initiative - or Star Wars - envisioned putting defensive weapons into space, as well as huge number on the ground.
The new national missile defence programme, on the other hand, would only deploy a small number of ground-based weapons.
It also incorporates some new technologies, such as the hit-to-kill kinetic energy weapon, Thaad.
Would it be in breach of existing nuclear treaties?
The 1972 anti-ballistic missile treaty, signed by the US and the USSR, forbids the development of a nationwide defence system.
So if the US were to go ahead, it would either need the agreement of Russia to amend the treaty - or it would unilaterally reject the treaty.
Talks between Washington and Moscow have begun, but so far Russia appears firmly opposed to anything which it believes might weaken the effectiveness of its nuclear deterrent.
How is the UK involved?
The UK Government shares the scepticism of other European countries.
It has not yet had any formal request for assistance. But the US is reported to have suggested that the existing US base at Flyingdales and the communications installation at Menwith Hill should be upgraded.
If the UK were to agree, it would benefit from more effective radar warning systems, although there are no interceptors in Europe.
Critics say it could also increase the UK's potential vulnerability as it would be seen as a US ally, while not actually being covered by a defensive screen.
Any UK involvement would be likely to trigger a wave of anti-nuclear protests.
Would other countries be involved?
There are also US proposals to install radar and communication installations in Greenland, technically under the sovereignty of Denmark.
But many European countries are sceptical about the plans.
They are worried about the US pursuing a unilateral defence policy, and provoking Russia.
There is also concern that a defensive screen for the US alone would leave the Europeans vulnerable.
Washington has begun discussing a regional defence system. But the Americans have yet to win the support of their Nato partners. And the Chinese have warned that they might be forced to boost their own military deployments if the system is given to South Korea, Japan or Taiwan.