Gregbo: The parade started at the Arc de Triomphe (closed during the parade) and ran the down the Champs Elysees. After the parade the Arc opened and the shops were all opened.

PWAbbott - My thanks for that information. May I ask if you know if it is possible to go up to the top of the Arc before the parade and view it from there?
Much obliged.

Tod:I don't think so. We did not know about the parade and tried to take the metro to the Arc station and had to get off one stop before that because the Arc was closed during the parade. Lots of security issues in this post 9/11 world. There were all kinds of diplomats from other countries and the French president laid a wreath on the tomb of the Unknown Soldier.

I'm almost positive that you cannot watch the parade from the top of the arc. (Obviously, if that was possible, keep in mind that there'd be a very long line waiting to get up there, so you chances of getting up there would have been slim unless you went in line many hours earlier. However, it's all academic since you can't get up there!)
Just make sure you walk to and thru the arc that day or the next one. The massive flag that hangs under the arc on those days is only there at that time and one other time during the year. (I forget what the other occasion is.)