Forces Driving Imperialism

I think that there are a few different forces driving imperialism, one of the MAIN causes of WWI.  First off is the potential gain in resources that could be made through imperialism was a very appealing factor to the select nations that had the power at the time to actually carry out imperialism.  Also, in response to the other nations' imperialism, the nations that did not participate would eventually fall behind in the race to become a world power. In relation to WWI I think the most important factor is the foothold that a nation could take in different areas around the world.  This foothold could provide a nation with strategic bases and resources that were spaced out across the globe for easier access for their military.  This would be a major advantage in the event of a world war, and this is why so many nations pursued the path of imperialism.