Williams' first deployment was to Afghanistan and, on April 6, 2008, his unit was tasked to capture or kill high-value targets in the Shok Valley.

As the assault element was moving up a mountain toward its objective, it was engaged by intense enemy machine gun, sniper, and rocket-propelled grenade fire.

The lead portion of the assault element, which included the ground commander, sustained several casualties and became pinned down on the sheer mountainside.

Under withering fire, Sergeant Williams and his local national commandos fought up the terraced mountainside to the besieged element.

Sergeant Williams then fought and climbed his way back up the mountainside to help defend the lead assault element that still had several serious casualties in need of evacuation.

Noting that the collection point was about to be overrun by enemy fighters, Sergeant Williams led the Afghan commandos in a counter-attack that lasted for several hours.