Not sure on this but I was told it is because they are always supposed to be moving forward and the flag displayed the correct way would look as if they were in retreat. That could just be an old wives tale.

From: http://www.usflag.org/flagpatch.html "Why is the Flag patch "backwards" on Military uniforms? Following is a quote from the Department of Defense website... "Thank you for your inquiry about the proper placement of the American flag on the uniform of the U.S. Armed Forces. Army Regulation 670-1, “Wear and Appearance of Army Uniforms and Insignia,” updated most recently September 5, 2003, addresses explicitly the proper and lawful placement of the U.S. flag patch on the Army uniform. The regulation states that when authorized for application to the proper uniform the American flag patch is to be worn, right or left shoulder, so that “the star field faces forward, or to the flag’s own right. When worn in this manner, the flag is facing to the observer’s right, and gives the effect of the flag flying in the breeze as the wearer moves forward. The appropriate replica for the right shoulder sleeve is identified as the ‘reverse side flag’.” We appreciate and share your concern for the respectful display of our American flag on the uniform of the U.S. Armed Forces." For more information on Army Regulation 670-1 please visit the following web site, http://www.usapa.army.mil/pdffiles/r670_1.pdf"

I believe it was also used "backwards" on the right sleeve in Desert Storm to help ID phony US uniforms used by Iraqis for propoganda or other purposes.

So it looks like it is waving in the wind as they march into a battle. Otherwise, it would be flapping in the breeze as they retreated.

Jennifer is half right...the meaning behind the stars facing forward is because the stars never retreat in a battle.

The United States flag is worn on military uniforms "backward" (star field on right) to give the apperance of rushing forward into battle. To the observer the stripes flutter in the wind when charging forward into battle. and the patch is always worn on the right shoulder because in the military the "place of honor" is to the right according to U.S. Army regulations and the United States Code. (When a flag is on a pole the stripes flutter in the wind.) Note: when the flag is hung from a wall or ceiling vertically the star field is on the right. http://www4.law.cornell.edu/uscode/4/ch1.html

As a US Army Infantry veteran I can tell you that the answers saying "facing into battle" are what I know to be correct. That said, It's not that the flag is "backwards" at all as all flags have two sides. We are just used to seeing it one way because it's the standard that if the flag is to be displayed with only one side showing, the stars are always to the left. The uniform is one exception to it.

it's only flown "backward" on US Army uniforms. All other services wear it on the left shoulder (Air Force/Navy/Marine Corps flight suits, etc). The Army wears it on the right sleeve because tradition places the unit designation on the left sleeve. It flies "backward" because of the reasons already given...to make the flag advance as the wearer moves forward. Military aircraft and vehicles follow similar rules (tradition view on port side, "backward" view on starboard.