The correct answer is "a new era of peaceful European interstate relations had begun."
Prussian leadership of German unification meant a new era of peaceful European interstate relations had begun.
After so many years of confrontation and armed aggressions, the different regions of Germany could be unified under one nation under the leadership of military officer Otto Von Bismarck
A major factor in bringing about the unification of Germany was Prussian military power.
William 1 of Prussia was proclaimed German emperor on January 18, 1871, as a result of the German unification. Germany started its political and administrative life as a national state, as was the decision of the Princes of the German territories agreed at the end of the Franco-Prussian War. After the Franco-Prussian War in the 1860s, Otto von Bismarck and the Prussian Army played a big role in the unification of 1871.