Donald Rumsfeld: We must act to prevent a greater evil, even if that act means war

The US Defense Secretary, on why the war against terror must be taken to Saddam

This week, the US pauses to remember the 11 September attack on America – the innocent victims, the unexpected heroes, the courageous survivors, and the hundreds of millions of Americans whose unity and determination in the face of unprecedented evil have once again defined the spirit of America for all to see.

This week, the US pauses to remember the 11 September attack on America – the innocent victims, the unexpected heroes, the courageous survivors, and the hundreds of millions of Americans whose unity and determination in the face of unprecedented evil have once again defined the spirit of America for all to see.

It is important to remember that 11 September was not an attack on America alone, but an attack on people throughout the world who believe in freedom, who practise tolerance, and who defend the inalienable rights of man. Those precepts are the direct antithesis of terrorism, which seeks to intimidate, dominate and subjugate free men and women through fear and devastation.

The history of terrorism is long. It is not a new phenomenon, as many other nations know well. What is new is the level to which terrorists are willing to take their murderous deeds to ensure that the death and destruction they visit upon the innocent are greater than ever. What's new, as we saw in Afghanistan, is the ability of terrorist organisations completely to take over and occupy a country, co-opt a culture and oppress an entire people. What's new is the nexus between terrorist networks, terrorist states and weapons of mass destruction that, when combined with missile technology, can make mighty adversaries of small or impoverished states, or even relatively small groups of individuals. Left unchecked in a world where the global nature of finance, communications and transportation makes it possible for even isolated individuals or organisations to have global reach, terrorism presents the potential for destabilisation on a scale unmatched in previous eras.

Such is the nature of terrorism today. It is, as President Bush has said, "a threat with no precedent" – a threat that cannot be appeased, cannot be ignored, and must not be allowed to dominate our future or the future of the world.

Last year, in a bold and courageous act that recognised both its deep roots and its terrible potential, George Bush declared war on terrorism – not just against the perpetrators of the deadly attacks on America on 11 September, but against terrorists and their organisations and sponsors worldwide.

His was an act, backed by a united citizenry, that recognised America's role and responsibility to lead the world in freedom's defence. And, worldwide, freedom-loving nations joined us in the fight. To date, 90 countries – nearly half of all the nations in the world – have taken freedom's side, seizing terrorist assets and sharing intelligence; providing airlift, basing and over-flight rights; clearing mines and contributing forces, some of whom have already paid the ultimate price.

To be sure, there are those who question whether such a war is necessary, who hope, beyond all evidence to the contrary, that the terrorists are few in number, that the violence will not spread, that the acts will not escalate in number or intensity, that the weapons used in the future will not be more terrible than those used in the past, that deterrence or diplomacy or worse – appeasement – will somehow succeed where it has already failed.

But indications are otherwise, leaving the solemn realisation that sometimes the consequences of not acting can be more terrible than choosing to act, even if the act is war.

There are several things we know for certain. We know that weapons of mass destruction are appropriately named. We know that we live in a world in which these weapons not only exist, but are proliferating. We know there are terrorist states that currently possess weapons of mass destruction, and other terrorist states that are actively seeking to develop or acquire them. We know that these states have relationships with terrorist groups and terrorist networks. And we know that neither terrorist groups nor terrorist states would hesitate to use weapons of mass destruction if they believed it would serve their purposes.

We also know that, unlike wars of the past, in which time was required to amass and position great armies or navies to defeat an enemy, weapons of mass destruction can be developed in secret and deployed without warning, leaving little time for the targeted nation to discern intentions or formulate a response.

If this were to be the case, then a decision about whether or not we are at war could already have been taken. But even if it were not, recognising a risk so great, and a margin for error so small, what is the responsible course of action for free nations? Waiting until not thousands but tens of thousands of innocent people have been killed, or acting in anticipatory self-defence to prevent such an event from occurring?

On 11 September, the terrorists who perpetrated their evil deeds against America successfully accomplished exceedingly complex and exquisitely timed acts of terrorism but, despite their precision, they made a huge miscalculation. They concluded that Americans would cower and hide, that the government of the United States would not undertake a worldwide response using all the financial, diplomatic, economic and military resources at its disposal. They believed that their financial networks were secure, that their sanctuaries would protect them, and that the world would have no stomach for such a fight.

They were wrong on all counts.