There are a number of reasons.
Perhaps the most significant is the sense that there is a huge fund of community support for peace (as opposed to war) that is not yet expressing itself fully. The time has come for those of us who are unhappy about the actions of the US and Australian Governments to stand up again and repeat the things we were saying in 2003. Three years is three years too long. The suffering that has taken place is inexcusable.
Then there are all
the arguments about why the situation in Iraq is so unacceptable.
Here are
some examples:-
From Ross Blade (link)
From Nick Deane (email)