What if, in the pre-WWI era, France would have built forts along its border with Belgium?
Would this have caused Germany to launch a preventative strike on France?
Also, if France would have actually been able to complete this construction, would Germany (and also Austria-Hungary) have been much more cautious about sparking a general European war? After all, if France's border with Belgium becomes fully fortified, then the Schlieffen Plan becomes obsolete.
Any thoughts on all of this?