US Military Flags
A plain white flag is the international symbol of surrender or truce. The flag indicates peace and is usually flown or waved in times of war. Soldiers who are carrying a white flag should not be fired on and in turn they should not fire upon anyone. If an individual negotiator is carrying the white flag it means he is unarmed and has come in peace with the intent to surrender or negotiate.
A white flag is made of any material available at the time and it is the symbol itself, not the flag, which signifies its meaning. A white hanky or white paper may be used to indicate the person's intentions. People carrying the white flag are expected to remain neutral and are not allowed to participate in war-like acts.
The use of a white flag to fool or trick the enemy is forbidden and considered to be a war crime, which is a punishable offense by international law. The use of the flag to surrender is included in the Geneva Convention, which is a treaty that is supposed to be followed in times of war.
Years before the white flag, it was common for surrendering soldiers to hold their shields over their heads. It is believed white was used because it was readily available and it was a stark contrast to the colorful war banners that were used in battle. In the recent war in Iraq, Iraqi soldiers were often stripped of all articles of white clothing by their commanders to stop them from surrendering to American troops. Thankfully they were able to surrender by raising their hands above their heads.
Historians believe the use of a white flag to surrender dates back to the Eastern Han dynasty of 25 AD - 220AD and maybe even earlier.
The royal standard of France was once a plain white flag which then had a fleur de lys added to it before becoming the present day flag.