Smoke Screen Marines assigned to the 1st Marine Division use white phosphorus rounds to create a smoke screen during a fire support coordination exercise as part of Steel Knight 23 at Marine Corps Air Ground Combat Center Twentynine Palms, Calif., Dec. 1, 2022. Steel Knight is an annual combined arms live-fire exercise that is designed to ensure the division is optimized for naval expeditionary warfare in contested spaces and purpose-built to facilitate operations afloat and ashore. SHARE: Download: Full Size (2.35 MB) Tags: training, Marine Corps, Steel Knight 23 Credit: Marine Corps Lance Cpl. Earik Barton VIRIN: 221201-M-HW569-1776Y.JPG Photo Gallery