For those who are interested in writing history off of primary sources about the Cold War and terrorism, you can always count on the National Security Archives, which host declassified information online.
For example,
this story documents the decision making for how many people to send to Iraq.
You will see how they believed that only 5K soldiers would be needed by the end 2006. Instead the U.S. sent 30K more at the beginning on 2007.
This is the address for this source:
National Security Archive