Why did people oppose the Iraq War?

Answer 1

People opposed the Iraq War for a variety of reasons. The primary ones are as follows:

• There was no immediate or clear threat to the United States.
• One of the major arguments made by the Bush administration was that Iraq was supporting al-Qaeda, for which there was no evidence.
• The motives for the war were unclear, with many speculating that the motives were actually to gain access to petroleum or to fulfill the needs of military contractors like Cheney's Haliburton.
• General opposition to war in any case.
• Anti-Imperialist views and opposition to the expansion of US influence on the international stage.
• Skepticism over the presence of "weapons of mass destruction" in Iraq
• Belief that diplomatic solutions were effective in nullifying any threat from Iraq (be it al-Qaeda support or "weapons of mass destruction" removal")
• Belief that the invasion of Iraq would destabilize the wider Middle East or give a new operating space for al-Qaeda and other terrorists
• Fear that an invasion of Iraq would erode US sympathy on the world stage gained from the September 11th Attacks.
  

To be entirely fair to the Anti-War movement, many of their beliefs and fears were later proved to be correct and justified.

To read about the reasons for the Iraq War, please see the Related Question: What are the causes of the Iraq War of 2003-2011?

Answer 2

Germany and France were in opposition to war in Iraq,

Answer 3

Some people believe that the war was started because of the oil in the Middle East, others opposed it because they thought we didn't have enough intelligence to believe the had W.M.D.s

Answer 4

Iraq.