Aman ji
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/history-of-sikhism/27506-sikhs-europe-during-world-war-ii.html
Why not forward this thread to the US Department of the Army, Navy, Marines, Coast Guard, and Air Force? The article ends with a story that makes a good point. If someone volunteers for combat and wants to retain his turban, then why not? Does wearing a turban put others in danger? If it does, then how? Maybe also send it to President Obama. :)