Spain is not withdrawing because the coalition operations in Iraq are "illegal". Zapatero's campaign pledge was to withdraw troops if the UN did not take control of post war Iraq. I reject the opinion that removing Saddam was an illegal act, but if you assume it was for that sake of argument, then the UN taking control of post war Iraq would not remove the illegality of the invasion and overthrow. If it was illegal to overthrow Saddam prior to the overthrow, it would still be illegal afterward even if the UN took control of issuing construction contracts and training security forces. It's the same with your personal arguments. You've blasted the US for overthrowing Saddam and gone on and on about no WMD, but you have said on more than one occasion that you would have been totally on board if the UN had blessed the operation. You post that there are no WMD, we are killing civilians, Saddam couldn’t have hurt the US. If the UN backed 1441, we still would not know where the WMD are, civilians still would have died (probably many more), and Saddam still would not have been a threat. That is a logical disconnect to me.
Zapatero and those that elected him are cowards who gave in to terrorist demands. Nothing more, nothing less.