Last night I repeated the Washington Post in noting that the final combat unit — 4th Stryker Brigade, 2nd Infantry Division — was leaving Baghdad, formally ending Operation Iraqi Freedom.

Today a civilian with the U.S. Army Training and Doctrine (TRADOC) Command e-mails me to clarify:

The Army has three types of brigade combat teams (BCTs): Stryker, Infantry, and Heavy.

There will be five to six security assistance force brigades left in Iraq after 1 Sept. The only difference between a security assistance force brigade and a BCT is the addition of roughly 40 senior officers and noncommissioned officers who are there to help train Iraqi security forces. These 40 individuals draw upon the resources of the BCT to which they are assigned for additional instructors, demonstration troops, and security. These security assistance force brigades have the same combat capabilities as their base BCT structure. So saving that the final U.S. combat brigade leaves Baghdad is factually incorrect.

Duly noted. The most trying and bloodiest parts of the Iraq War are, we hope, behind us. But our involvement there is hardly over, not with 50,000 Americans still on the ground.