umm what? Ok i'll bite
The Old Republic was a democratic Republic, the Empire was not. Palpatine manufactured a war to put himself in a position of power (not to mention in control of an army). He then uses said army and Darth Vader to kill off the witnesses in the Confederacy that have any knowledge of his involvement, and then uses said army to purge the Jedi. He then, as mentioned in A New Hope, dissolves the Senate, leaving the ultimate authority to Palpatine, ruling the Empire as a Military Dictatorship, ruling out of fear with an iron fist. Blowing up Alderaan was an interrogation tool for Leia, but also a Weapons Test, and a warning for other planets to stay in line. The Empire was severely xenophobic, regularly enslaving other species, such as wookies. That's where Han met Chewbacca, Chewie was getting whipped and Han went against the officer whipping him, causing him his Imperial Pilot career.
So while the Imperial Army and Navy can claim they were just following orders, as much as any military, can, The Empire was an evil corrupt organization.