Ka-boom or bust: The U.S. missile defence system

In the 1980s, U.S. President Ronald Reagan talked about the Strategic Defence Initiative, the so-called Star Wars missile defence system that would shield the United States from Soviet missiles.

The blueprints mapped out a system that would shoot down missiles from space before they entered American airspace.

It was bold, ambitious and expensive but it never got off the ground. Critics argued strenuously that such a system would only lead to another arms race and, for a variety of reasons, missile defence was well down on the agenda in the administrations of George H.W. Bush and Bill Clinton.

Missile defence never found much favour within Canada's Liberal governments during that period as well. Though Paul Martin's government came close to joining the U.S. plan andit was given new life under the Stephen Harper Conservatives.

More recently, the missile defence ideahas energized debate and Cold War-like tensions inwestern Europe with Poland's decision in early 2008 to join the system and accept U.S. interceptor missiles on its soil.

As things now stand, at least three of Russia's former European satellites Poland, the Czech Republic and Ukraine want to participate in the missile defence system. In response, Russia has said it may arm its recently beefed-up Baltic fleet with nuclear-tipped warheads.

Reagan's legacy

In the U.S., The National Missile Defence Act of 1999 stated:

"It is the policy of the United States to deploy as soon as is technologically possible an effective National Missile Defence system capable of defending the territory of the United States against limited ballistic missile attack (whether accidental, unauthorized, or deliberate) with funding subject to the annual authorization of appropriations and the annual appropriation of funds for National Missile Defence."

But in the late 1990s, in the later years of the Clinton presidency, not much money was allocated to missile defence research.

That changed in the days after the attacks on Washington and New York City on Sept. 11, 2001. President George W. Bush made defence of the U.S. from missiles fired by "rogue states" a priority.

Two months after the Sept. 11 attacks, Bush took an important geopoliticalstep, announcingthat the U.S. would pull out of the Anti-Ballistic Missile Treaty.

Under that treaty with the former Soviet Union, both sides were severely restricted from developing missile defence systems. The idea was to maintain a level of strength on each side that would deter either from firing its nuclear missiles at the other.

Critics of Washington's decision predicted pulling out of the treaty would lead to another escalation in the arms race, this time involving much smaller countries. Supporters argued the move was needed to allow the U.S. to protect itself from nuclear blackmail.

In December 2002, Bush directed the military to devise a defensive system that would protect the U.S., its forces abroad and its allies and friends from the threat of ballistic missiles, leading to the missile defence system in its current form.

What it is

The ballistic missile-defence system is designed to give the U.S. the power to protect itself from incoming intercontinental ballistic missiles (ICBMs), whether launched by accident or as an attack from rogue states.

As of January 2008, the Missile Defence Agency reports that the system consists of:

• 24 ground-based interceptors at Fort Greely, Alaska, and Vandenberg Air Force Base, Calif.;
• 10 navy ships cruisers and destroyers carrying long-range surveillance and tracking systems, called Aegis;
• 21 interceptors based on Aegis-capable ships;
• Upgraded radar facilities in Alaska, California and the U.K.;
• Three X-band radar systems, transportable by air, sea or rail.

How it works

The missile defence system is based on a web of ground- and sea-based sensors. If one set of the sensors detects an object headed for the U.S. or one of its missile defence allies, the information is relayed to the rest of the system, which tracks the object's trajectory.

If the object is identified as an incoming missile, a ground- or marine-based missile is launched to intercept it.

The missile is guided based on coordinates provided by sensors tracking the incoming missile. If this is unsuccessful, the process is repeated.

The incoming missile is knocked out by the energy that is transferred in the collision between the two missiles. There is no explosion, but debris from the collision may burn up as it enters the Earth's atmosphere.

It is one of the most complex weapons systems ever designed. Military officials describe the process as trying to hit a bullet with another bullet and, until only recently, many tests of the technology have failed.

In January 2000, for example, the U.S. military conducted a mock nuclear attack. A Minuteman ICBM, designed to carry a nuclear warhead, was launched from Vandenberg Air Force Base in California. Twenty minutes later, another smaller missile was launched from the Marshall Islands about 7,000 kilometres away. The second missile was supposed to hit the first, but missed.

This was the pattern throughout much of the past few years, though the U.S. Missile Defence Agency saysat least 14recent tests have been far more successful.

Broadening the scope

The U.S. has proposed expanding its missile defence capabilities to Europe with a ground-based missile interceptor site in Poland and an X-band radar site in the Czech Republic.

In addition to the land-based missile defence measures, the U.S. is looking at developing even loftier technologies. The Pentagon hopeseventually to launch aircraft-mounted lasers capable of directing energy to destroy incoming missiles. It also hopes to develop an array of space-based missiles capable of destroying ICBMs.

In January 1999, the Russian newspaper Nezavisimaya Gazeta called the BMD system an attack on Russia aimed at "overcoming the last remaining barrier to American world domination."

Washington assured Russia it had nothing to worry about, saying the system was intended to protect against possible threats from countries such as Iraq, Iran and North Korea, which the U.S. had alleged possessed weapons of mass destruction capable of reaching its interests.

Russian President Vladimir Putin called the move a "mistake," but said he did not feel it would threaten Russian security.

In early December 2003, Australia announced it would join the defence shield.

"We believe that taking part in the U.S. program will serve our strategic interest, help us defend Australia and allow us to make an important contribution to global and regional security," said Foreign Minister Alexander Downer in a statement.

In February 2005, after months of deliberation, then-Liberal foreign affairs minister Pierre Pettigrew told the House of Commons that Canada would not participate in the U.S. missile defence program.

One year and one election later, the new Conservative defence minister Gordon O'Connor (currently the revenue minister) said the Conservative government was open to restarting talks on missile defence with the U.S.

When Poland announced in 2008 that it would allow the U.S. to place a missile interceptor base on its soil, a Russian general told reporters that Poland "cannot go unpunished." "Poland, by deploying [the system] is exposing itself to a strike 100 per cent," said Gen. Anatoly Nogovitsyn, deputy chief of the Russian general staff.