George Soros: Why I have campaigned across America to put John Kerry in the White House

He is nuanced because reality is complicated. That is exactly the character we need in our commander-in-chief

I have been criss-crossing the United States for the past three weeks, arguing against the re-election of President Bush. I feel strongly that he has led us in the wrong direction. The invasion of Iraq was a colossal blunder, and only by rejecting the President at the polls can we hope to escape from the quagmire in which we find ourselves.

I embarked on the tour because I was worried that the dramatic deterioration in Iraq did not produce the decisive lead for John Kerry I had confidently expected. Now that I am at the end of my tour, I am not reassured. Kerry and Bush are neck and neck in the polls, and although I believe voter turnout is likely to give Kerry the victory, the race is too close for comfort.

The nation is deeply divided, and the two camps seem to be talking past each other. John Kerry won all three debates, but President Bush invokes his faith and that inspires his followers. In the end, it boils down to a philosophical difference over how to deal with an often confusing and threatening reality.

An open society such as ours is based on the recognition that our understanding of reality is inherently imperfect. Nobody is in possession of the ultimate truth. As the philosopher Karl Popper has shown, the ultimate truth is not attainable even in science. All theories are subject to testing, and the process of replacing old theories with better ones never ends.

Faith plays an important role in an open society. Exactly because our understanding is imperfect, we cannot base our decisions on knowledge alone. We need to rely on beliefs, religious or otherwise, to help us make decisions. But we must remain open to the possibility that we may be wrong so that we can correct our mistakes. Otherwise, we are bound to be wrong.

President Bush has shown he is incapable of recognising his mistakes. He insists on making reality conform to his beliefs even at the cost of deceiving himself and deliberately deceiving the public. There is something appealing in the strength of his faith, especially in our troubled time. But the cost is too high. By putting our faith in a President who cannot admit his mistakes, we commit ourselves to the wrong policies. We are the most powerful nation on earth. No external power, no terrorist organisation, can defeat us. But we can defeat ourselves by getting caught in a quagmire. Leaders who claim to be in possession of the ultimate truth offer an escape from uncertainty. But that is a snare, because those leaders are bound to be wrong.

Under the influence of globalisation, we have been exposed to more than a normal dose of uncertainty. That is why the kind of faith that guides President Bush is so appealing. The traumatic events of 9/11 have reinforced that appeal. President Bush rose to the occasion and he carried the nation behind him. But he has led us in the wrong direction. If we re-elect President Bush, we are endorsing his policies and we shall have to live with the consequences. We are facing a vicious circle of escalating violence with no end in sight. If we reject him at the polls, we shall have a better chance to regain the respect and support of the world and break the vicious circle. Our future depends on it.

That is why I consider this the most important election of my lifetime, and that is why I have taken such an active role in it. I have devoted half my fortune and most of my energies in the past 15 years to promoting the values of democracy and open society all over the world, especially in the former Soviet empire. After 9/11, I came to feel that those principles need to be defended at home.

All my experience in fostering democracy and open society has taught me that democracy cannot be imposed by military means. And the way we went about it in Iraq will make it more difficult to promote democracy in the future. Through my foundation network devoted to promoting democracy and open society worldwide, I feel this personally. Under President Bush, America has lost its credibility as a champion of open society.

Instead of admitting his mistakes, President Bush now tells us that offence is the best defence, and we are safer at home because we are fighting the terrorists abroad. The argument resonates strongly with an electorate fearful of terrorism - but it is a Siren's song. Let me explain why.

The war on terror is an abstraction. But the terrorists are real people and they are not all alike. Most of the people attacking our soldiers in Iraq originally had nothing to do with al-Qa'ida. They have been generated by the policies of the Bush administration. We have been spared a terrorist attack at home, but it is quite a stretch to attribute that to the invasion of Iraq. The insurrection in Iraq, however, is a sombre reality, and it doesn't make us safer at home. Our security, far from improving as President Bush claims, is deteriorating.

Before the invasion of Iraq, we could project overwhelming power in any part of the world. We cannot do so any more because we are bogged down in Iraq. Iran and North Korea are moving ahead with their nuclear programmes at full speed, and our hand in dealing with them has been greatly weakened. There are many other policies for which the Bush administration can be criticised, but none are as important as Iraq. Iraq is the proof that we cannot put our faith in the President.

The war on terror as defined by President Bush is a one-dimensional presentation of reality. We cannot fight terrorism by military means alone. We can use military force only when we have a known target; but it is the habit of terrorists to keep their whereabouts hidden. To track them down, we need the support of the populations among whom they hide. Offence is not necessarily the best defence if it offends those whose allegiance we need.

John Kerry is aware of this other dimension. That is why he cannot be as single-minded as George Bush. He is nuanced because reality is complicated. This has been turned into a character flaw by the Bush campaign. Yet, that is exactly the character we need in our commander-in-chief. John Kerry is prepared to defend the country as he showed in Vietnam; but he has learned first hand the devastation that war can bring and will use military force only as a last resort.

By contrast, George Bush revels in being a war president. His campaign is shamelessly exploiting the fears generated by 9/11. But fear is a bad counsellor; we must resist it wherever it comes from. If we re-elect President Bush, the war on terror will never end. The terrorists are invisible, therefore they can never disappear. It is our civil liberties that may disappear instead.

An open society is always in danger. It must constantly reaffirm its principles in order to survive. We are being sorely tested, first by 9/11 and then by President Bush's response. To pass the test, we must face reality instead of finding solace in false certainties. Our future as an open society depends on resisting the Siren's song.

The writer is an American financier and philanthropist