[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/12/31/art.security1231.gi.jpg caption="What missed signals cleared the way for Umar Farouk AbdulMutallab to board his flight on Christmas?"]Washington (CNN) - To understand how the suspect in the botched terror attack was able to board a plane, you have to understand how the counterterrorism system that President Obama says failed is supposed to work.
The president says the clues were there, and that a fuller, clearer picture of 23-year-old Umar Farouk AbdulMutallab would have emerged if all the bits and pieces had been shared and put together.
"The warning signs would have triggered red flags, and the suspect would have never been allowed to board that plane for America," Obama said.
The president has ordered a top-to-bottom investigation of the failed terrorist attack on Christmas Day. The preliminary report is expected Thursday.
One of the key questions is why wasn't the suspect's visa revoked.