It took Bismarck five years and three wars to unite Germany, with clever manoeuvring and diplomacy in between. It is questionable whether another leader in this period could have done this with success.
His first action was against the Danish over the issue of Schleswig-Holstein, in alliance with Austria so as not to upset any of the major powers too soon. .
Then, determined to exert Prussian dominance over German area, including Austria, and foreseeing war, Bismarck set up important alliances with Italy, who eventually provoked Austria into war, and France, who thought they would gain territory and power at the end of what Napoleon
thought must surely be a long power struggle between them, and so were to remain neutral.
However the Austro-Prussian war ended quickly in a decisive victory for Austria, leaving the French, the last major power Bismarck would have to deal with, feeling vulnerable and threatened by the decisive power shift. Again it was Bismarck's influence that provoked the final step to war, with him having an edited version of the Ems telegraph published so that the French Ambassador was humiliated. The French public would tolerate no more, Napoleon
had to react or his public would have gotten rid of him. .
On 4 August 1970 the fighting began and one month later they were defeated at Sedan. In January 1871 the French accepted the armistice, leaving the way clear for Bismarck to unite Germany, and helped by the pressure a surge of popular patriotism put on them, he forced the southern states to join.
It is certain that Bismarck was highly influential in the short-term issue of geographically uniting the German states, but other, perhaps more critical, measures of his influence would be politically and socially in the long-term after unification; whether or not he could successfully unite the people from these varied states. .
Bismarck had set up the constitution to his own advantage.