TOPEKA, Kan. (AP) _ A former Fort Riley infantry commander has documented the lessons he learned in Iraq and gives a warning the Army should not soon forget.

Lt. Col. Jim Crider deployed to Iraq with the 1st Squadron, 4th Cavalry Regiment from Fort Riley in 2007. His unit was part of the surge of troops sent there to quell violence.

In his essay, published by the Center for a New American Security this week, Crider acknowledges that he didn't fully understand the conditions he was facing. He learned quickly that he couldn't use traditional military tactics.

Crider says he and his soldiers learned that small groups making a concerted effort to know their neighborhoods and its residents helped establish trust and cooperation with Iraqis.

This eventually led to reduced violence and a give-and-take relationship.

(Copyright 2009 by The Associated Press. All Rights Reserved.)