Could World War Two have been avoided?

In my opinion, WWII was bound to happen.  With the Nazis rising to power, the world had to do something.  If they just stood back the whole time, the whole world would either be under the Nazi's power or the communists' power.  Our world would be a totally different place.  Hitler tried to make it seem like he meant well, but in reality, he was just another power-hungry leader wanting to take over as much land as possible.  There was still a lot of tension from WWI that had to be dealt with.  It almost seemed as if there was no point in the Allies winning WWI, because it just made more tension than there already was.  The Treaty of Versailles was so harsh, and they should have realized that the Germans were bound to fight back.  It's little things like this that go unthought about, and it could make or break the entire war.