WI: Defensive-Minded Great Power Pre-WW1

Imagine a scenario in which one of the major military planners of one of the great powers in the years leading up to WW1 takes stock of modern technology and concludes that, despite the common conception of offensive-oriented wars of maneuver being pre-eminent, the next war will likely be defensive in nature, with machine guns, artillery, and trench warfare dominating the battlefield for the foreseeable future. What are the results? I think the biggest opportunity for change would be in France, so lets focus there. Lets also assume that the war starts, more or less, right on schedule.
 
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