But there’s another reason Shinseki is hard for the president to dismiss. The retired general has for years been a particular hero to Obama’s supporters on the left for his conflict with the George W. Bush administration during the run-up to the war in Iraq.

In early 2003, as the U.S. was planning the invasion, Shinseki angered his superiors in the Pentagon and White House by saying he believed victory and post-war stabilization in Iraq would require far more U.S. troops than President Bush and Defense Secretary Donald Rumsfeld were planning to deploy. “Something on the order of several hundred thousand soldiers are probably, you know, a figure that would be required,” Shinseki told Congress in February 2003.

Shinseki was criticized, even vilified, for his position. Pushed away from the center of Pentagon power, he retired a few months later, in June 2003.

The Bush administration went ahead with its plan to invade Iraq with a significantly smaller force than Shinseki recommended. Later, when Iraq collapsed into chaos, some of the war’s strongest supporters conceded Shinseki had been correct. “We never had enough troops to begin with,” Republican Sen. Lindsey Graham told the New York Times in 2007. “A month or two ago we found out the Army is broken, and they agreed that General Shinseki was right.”