I have no idea what ‘redpilled’ means.
But regarding Iraq I thought that the PNAC, Democracy Project inspired plan to remove Saddam and ‘convert’ Iraq was utopian lunacy at its highest. And unfortunately that proved out to be true at great cost.
It refers to the scene in the movie Matrix, where the hero Neo (K. Reeves) was offered the red pill or the blue pill. If he took the red pill he see the truth, and if he took the blue pill he would continue in his unreal fantasy world. So being "redpilled" means you have chosen to see the truth.