It's a very old symbol of peace (!!!), luck and happiness (!!!)
The word "swastika" comes from the Sanskrit svastika - "su" meaning "good," "asti" meaning "to be," and "ka" as a suffix.
Until the Nazis used this symbol, the swastika was used by many cultures throughout the past 3,000 years to represent life, sun, power, strength, and good luck. Also resurrection and the return of the wheel of life.
Even in the early twentieth century, the swastika was still a symbol with positive connotations. For instance, the swastika was a common decoration that often adorned cigarette cases, postcards, coins, and buildings. During World War I, the swastika could even be found on the shoulder patches of the American 45th Division and on the Finnish air force until after World War II.
In the 1800s, countries around Germany were growing much larger, forming empires; yet Germany was not a unified country until 1871. To counter the feeling of vulnerability and the stigma of youth, German nationalists in the mid-nineteenth century began to use the swastika, because it had ancient Aryan/Indian origins, to represent a long Germanic/Aryan history.
when i was in iran during the end of the last shah's reign, i was astounded to see swastikas at some of the old ancient installations. i was assured that the swastka had been there before the germans. and indeed, in the 30s the nazis "allied" briefly with the iranians, looking at them as either "big brother aryans" or as "little brother aryas" either way as those who had "lost" their "aryan way of leadership.
By the end of the nineteenth century, the swastika could be found on nationalist German volkisch periodicals and was the official emblem of the German Gymnasts' League.
In the beginning of the twentieth century, the swastika was a common symbol of German nationalism and could be found in a multitude of places such as the emblem for the Wandervogel, a German youth movement; on Joerg Lanz von Liebenfels' antisemitic periodical Ostara; on various Freikorps units; and as an emblem of the Thule Society.
In ancient times, the direction of the swastika was interchangeable as can be seen on an ancient Chinese silk drawing.
Some cultures in the past had differentiated between the clockwise swastika and the counter-clockwise sauvastika. In these cultures the swastika symbolized health and life while the sauvastika took on a mystical meaning of bad-luck or misfortune.
But since the Nazis use of the swastika, some people are trying to differentiate the two meanings of the swastika by varying its direction - trying to make the clockwise, Nazi version of the swastika mean hate and death while the counter-clockwise version would hold the ancient meaning of the symbol, life and good-luck.