The Bush administration has repeatedly lied to support the war  

From the time that the Bush administration began pushing for war in Iraq they have repeatedly made press statements that have proven to be false and statements made on unsupported information.  This has been done to inspire a feeling of fear among the public with the hope that people would support the war out of a fear of imminent attack from Saddam Hussein.

In discussing the resignation of Rand Beers from the National Security Council James Bamford, author and intelligence expert, said that:

"There is a predominant belief in the intelligence community that an invasion of Iraq will cause more terrorism than it will prevent. There is also a tremendous amount of embarrassment by intelligence professionals that there have been so many lies out of the administration -- by the president, (Vice President Dick) Cheney and (Secretary of State Colin) Powell -- over Iraq."  - March 19, 2003

http://www.globalpolicy.org/security/issues/iraq/attack/statement/2003/0319bossresigns.htm

Below is a short list of some of the lies that have been told in order to support the war (linked are both original news stories as they appeared and new pieces after they were debunked ):

1. There will be no war if Saddam leaves.  This is false.  The plan was to invade even if Saddam did leave.  The premise for invasion was to be searching for weapons of mass destruction by American forces.  So it didn’t matter if Saddam left or not, the invasion would still have taken place.  
   http://www.fair.org/press-releases/ultimatum.htm

2. The Powell paper that was sited as a source of information for an address to the UN Security Council, and the world, which made statements about the Iraqi regime and its involvement with terrorist organizations and weapons of mass destruction, was later exposed as a paper written by a graduate student from California.  Prior to making the statement to the UN Powell said: "My colleagues, every statement I make today is backed up by sources, solid sources. These are not assertions. What we're giving you are facts and conclusions based on solid intelligence."  
   http://www.cnn.com/2003/WORLD/meast/02/07/sprj.irq.uk.dossier/index.html
   http://www.channel4.com/news/2003/02/week_1/06_dossier.html
   http://news.bbc.co.uk/1/hi/uk_politics/2736149.stm
   http://truthout.org/docs_02/020803A.htm

3. The claim that was made that put America on “code orange” and sent millions to the store to buy duct tape and plastic for their windows was later exposed as baseless.  The claim was that there was a “significant threat” of a massive chemical weapons attack on American soil “soon”.  This news terrified the country and had many running for cover.  Within a day, though, it was later exposed as baseless.  Of course there was no problem spreading the lie to promote a sense of fear in the public.
   http://www.foxnews.com/story/0,2933,78593,00.html
   http://www.cnn.com/2003/ALLPOLITICS/02/17/timep.edge.tm/index.html
   http://www.cnn.com/2003/ALLPOLITICS/02/14/homeland.security/index.html
   

4. The claim that Iraq had a fleet of unmanned aircraft that could possibly reach America and deliver weapons of mass destruction was quickly circulated in the press, it too turned out to be a lie.
   http://abcnews.go.com/sections/wnt/DailyNews/iraq_reality021008.html
   http://www.foxnews.com/story/0,2933,79450,00.html
   http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2002/10/08/wbush08.xml
   http://www.usatoday.com/news/opinion/2002-10-24-oped-bamford_x.htm
   
   
5. Bush sited a report that stated that the International Atomic Energy Agency said the Iraqis were six months away from developing atomic weapons.  There was actually no report at all.  This was pure fabrication.
   http://www.commondreams.org/headlines02/0927-08.htm
   http://www.washingtonpost.com/ac2/wp-dyn/A51871-2002Sep7?language=printer
   http://way.nu/archives/000422.html

This is just a short list of lies told by the Bush administration that are directly related to this current war, “Operation Iraqi Freedom”.

For a more extensive list of the Bush lies to support the war see:

http://www.politicalstrategy.org/2003_03_10_weblog_archive.htm

Update 12/2/2004:

237 Misleading Statements by the Bush administration

Iraq On the Record: The Administration's Public Statements on Iraq