Similarities and differences between the methods adopted by Otto von Bismarck and Sardar Vallabhai?

Otto Von Bismarck, the Iron Chancellor of Germany, used a combination of realpolitik, diplomacy, and military force to unify Germany under Prussian leadership in 1871. Sardar Vallabhbhai Patel, known as the Iron Man of India, played a crucial role in integrating over 500 princely states into the newly independent India through negotiations, diplomacy, and the threat of military force, known as the "iron fist in a velvet glove" approach. Both leaders were instrumental in unifying their respective countries through skillful diplomacy and strategic use of power, although in different historical contexts and circumstances.