How do we get into wars???

I love the Rachel Maddow show as she investigates issues more deeply and thoughtfully then most news channels. Given the 10th anniversary of the Iraq war she looks at how America declared war after 9/11. I think you'll find some interesting ideas of how governments get their countries into war and hopefully it will give you plenty to think about. For our purposes when looking at issues what does this commentary tell you and us about propaganda? Is it fair to suggest that what you see in the video was all contrived or was it also legitimate to get involved. Let me know your thoughts, the video can be found here.