Prussian leaders, especially Otto von Bismarck, the chancellor and advisor to Prussia's king, believed Prussia could be a united and respected power, but only without the traditional Austrian dominance. At the time, the Austrian empire was a collection of ethnically diverse peoples and had been dominated by a socio-political conservatism that sought to keep the empire ruled in Hapsburg tradition.

After Prussia was victorious in the Austro-Prussian War, Bismarck played a waiting game where the unification of Germany was concerned, as the joining of the southern states - initially resistant to Prussian rule, friendly with Austria, and bent on independence - would have to be overcome. What was needed was "a clear case of French aggression" toward either Prussia or the southern states. Not only would such a move by Emperor Napoleon III trigger the terms of the treaty between the German states, but it would keep the remaining world powers out of the conflict.

It would be a dispute over the throne of Spain that would cause Napoleon III to act. During a revolution, Queen of Spain Isabella was forced to flee Madrid. Spain was divided over who would rule, and the other European nations had a decided interest in the matter. In the months that followed, Prince Leopold of Hohenzollern was suggested as a fitting heir. His name, as well as many others, circulated amongst the powerful and the influential. Some have suggested Bismarck had orchestrated the naming of Leopold as successor to tie Spain to Germany, but most historians dispute his direct involvement in the matter. Leopold's attractions included the fact that he was "the husband of a Portuguese princess, related both to the royal house of Prussia and to Napoleon III, and with several sons to carry on the line."[3] Though many candidates were considered - including Leopold's younger brother, Charles, who was a ruling Romanian prince - they were deemed unacceptable to some party of influence in heavily fractious Spain, unacceptable to hold such a great power, or they were uninterested.

Needless to say, the First World War came at an unfortunate time for those who would fight in it. After an initial period of relatively rapid maneuver during which the German forces pushing through Belgium and the French and British forces attempting to stymie them made an endless series of abortive flanking movements that extended the lines to the sea, a stalemate naturally tended to develop. The infamous trench lines soon snaked across the French and Belgian countryside, creating an essentially futile static slaughterhouse whose sinister memory remains to this day.

If trench warfare was an inevitability during the war, it is only because the events leading up to the First Battle of the Marne were quite different. The armies at the beginning of the war moved quickly through the land, but the First Battle of the Marne devolved into a bloody pitched battle that led to the construction of trenches after the Germans retreated, blocked in their pursuit of Paris. When the aftermath disintegrated into a war between trenches, some Germans thought they had the upper hand since they were occupying French territory, but with fewer soldiers than the combined Allied nations and fewer resources and supplies, it was possibly only a matter of time before they were ultimately defeated. The commander of the German armies, General Helmuth von Moltke, allegedly said to Kaiser Wilhelm II immediately after the First Battle of the Marne, "Your Majesty, we have lost the war."