The Iron Cross (the style of which categorizes it as a Maltese cross) is simply a symbol of Germany. It was before the war, and remains so. For example, the German air force painted the iron cross on its aircraft in World War I. It did so in World War II. The German air force of today still paints the iron cross on its planes as a matter of identification.
Here is a simple comparison: The United States Air Force paints a star on its plaines to identify them. It has been doing this, with variations, since the years leading up to World War II (when it was known as the Army Air Force, as it was not an independent branch until circa 1947). This practice continues today. The star is an identifier; an observer can quickly ascertain a given military plane's national affiliation by the symbol it bares.
The Iron Cross has had many uses, other than identifying aircraft. It has been used on many types of military vehicles owned my Germany. It has been used as a military decoration; that is to say, it has been used as the centerpiece of medals awarded for meritorious service by German soldiers. I do not know if Germany continues this practice today.
Nothing evil has been attributed to the Iron Cross. That is, it is not generally considered an evil symbol or something to be feared. The swatstika, on the other hand, is something entirely different.
When seen, the swatstika draws up immediate feelings of disgust and images of the holocaust for many who view it. Never have I personally seen a symbol that invokes such an emotional reaction as the swatstika. Never before or since have I seen a symbol that embodies hatred and pure evil than the swatstika.
My grandfather returned from the war in Europe with a few flags in his possession. Each of them bares the swatstika. But most chilling of all, is the Nazi armband in his souvenir collection. I've held the armband in my hand. Though I have read many books on World War II and watched many movies on the subject, nothing has made it seem more real than holding the armband--the real thing--in my hand. Viewing it terrifies me. Though my grandfather left his souvenir collection to me when he died, I've only viewed the armband and the flags two or three times since, for so strong is my reaction to them.
In American it has since been adopted as a sign used by Biker gangs, I do not live in the USA, so I don't know any more.
I can answer the mini-question brought up by the last answer, the Iron Cross IS still used in Germany today, it has just never been awarded as it is a wartime-only award, and German has never been in any major wars since WW2.
The iron Cross originated in Prussia, which at the time was mostly made up of modern Germany, so obviously that is why it moved on to become a German award.
It was used in WW1 and was constructed exactly the same as the WW2 variant, only instead of a swaztika and 1939 written on it, it had 1913 and a 'W' - for Wilhelm, the Kaiser.
In WW2 Hitler moved on from the first and second class iron crosses to make many more variants, inluding the Knights Cross of the Iron Cross, with a few more that I cannot name, each one being awarded for more prestigious things. For every better variant it was awarded less often and generally to more important people than the lower medal classes.
The higher variants of the Iron Cross were awarded to the recipient by Adolf Hitler himself.
The iron cross, as I said before, has not been awarded since WW2, but should a major conflict arise involving Germany it will be awarded if it is deserved.
For anyone who didn't know, the Iron Cross was only mainly awarded for acts of Bravery in the German armed forces, as there were commonly only 1st and 2nd classes awarded, the 1st cless could only be received if you had already been awarded the 2nd class, however if the recipient carried out an extremely impressive act, then the 1st and 2nd classes could be awarded at the same time to get around this.
I am honestly quite impressed by my own knowledge of iron crosses after this!
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