Bush's invasion of a country that posed no threat to the US was illegal under both US and international law, according to legal experts. Bush has been convicted of war crimes by citizen tribunals around the world, including New York, Paris, Tokyo, and Istanbul. Just las week, the towns of Brattleboro and Marlboro Vermont voted to indict and arrest Bush and Cheney.

In 2002 and 2003, Bush led a propaganda campaign to defraud Congress, the American people, and key allies into believing Iraq was a threat. Bush claimed Iraq had stockpiles of chemical, biological, and nuclear weapons to use against the US, and was sharing them with Al Qaeda.

Speaking near Rochester NY, Bush later admitted, "See in my line of work you got to keep repeating things over and over and over again for the truth to sink in, to kind of catapult the propaganda."
...AlterNet

Even with an election coming up, how can the American public and their allies continue to support Bush's policies and continue fighting his war?

Congress is entirely complicit in the evil of this administration.