Greens Leader Christine Milne says mission creep in Iraq has accelerated and Prime Minister Tony Abbott has committed troops to an unwinnable war.
"Tony Abbott continues to blindly follow the US further and further into the Iraq quagmire. He has absolutely zero idea of what success would look like," Senator Milne said.
"The Prime Minister says he will review the deployment after 12 months but against what criteria? What will constitute success or failure, what will determine whether we stay or come home?
"The entire conflict is an intractable mess driven by sectarian hatred that is potentially being made even worse with US involvement. Australian involvement is not making us safer - it's the opposite.
"The Prime Minister said initially that there would be no boots on the ground. We've seen mission creep from day one.
"We have a situation where we have Shiite militias fighting alongside Iraqi troops, we have Iraqi special units under investigation for war crimes.
"There is no end to it. There will never be a clear idea of what victory would look like.
"The Greens totally support Australian troops. We always have and we always will. We do not support the government's decision to deploy them to Iraq."