Unless it just sets the stage for the next one the way the Franco-Prussian Wars did. Sometimes I think Bismarck was too successful for his own good; he seems to have been sincere in just wanting to integrate what he considered "German" territory into the nation proper, but by the time that goal had been achieved it had worked SO well that the Kaiser started buying into the whole "manifest destiny" line.

As to the other point you raise, I hadn't thought about it, but it's a good one. Without checking, I don't know what role Britains rivalry with the Netherlands from the Age of Exploration down to the colonial era had in England acting as Belgian Protector, but they might not have been as willing to stick their neck out for the Dutch. And, of course, if Belgium is just a French province it's to some degree another Franco-Prussian war (though I'm not sure ties between the British and Russian royal families wouldn't have dragged Britain anyway when Russia declared war on Germany in defense of Serbia, but Britain might have opted for neutrality to avoid another Crimean War. )