As their convoy reached the barbed wire at the border crossing out of Iraq on Wednesday, the soldiers whooped and cheered. Then they scrambled out of their stifling hot armored vehicles, unfurled an American flag and posed for group photos.

For these troops of the 4th Stryker Brigade, 2nd Infantry Division, it was a moment of relief fraught with symbolism. Seven years and five months after the U.S.-led invasion, the last American combat brigade was leaving Iraq, well ahead of President Barack Obama’s Aug. 31 deadline for ending U.S. combat operations there.

That presence is far from over. Scatterings of combat troops still await departure, and some 50,000 will stay another year in what is designated as a noncombat role. They will carry weapons to defend themselves and accompany Iraqi troops on missions. Special forces will continue to help Iraqis hunt for terrorists.

So the U.S. death toll — at least 4,415 by Pentagon count as of Wednesday — may not yet be final.