I found this flagged dead and vouched for it. That's not to say I have prior reasons to believe its claims; only to say that I think it's making an interesting argument and deserves discussion. If anyone who flagged it wants to say why, and chew me out for vouching for it, please, go ahead :-)
I think it makes sense that Saddam's own generals and military leaders had something to do with the rise of ISIS. They were thrown out of power in Iraq and denied pensions and everything. Had to find a way to make a living and get back in power at any cost.
Iraq had caches of suicide vests and other stuff that Saddam was planning on using. We discovered those things after the invasion.