Standard Beliefs (These are the same through every era): Generally most of the Imperial Armed Forces saw aliens as inferior. Some of the Imperials did not hold this belief but that is what held the Imperial Armed Forces together was its hatred of aliens. A few of the members of the Imperial Armed Forces joined only to protect the law. Most of the members of the Imperial Armed Forces were not evil only misguided.
Rebellion Era: During the Rebellion Era many of the people who joined the Imperial Armed Forces saw it as the protector of law and order. The Empire may have ruthlessly oppressed alien races but that was just to maintain safety and order for the good of the people. Imperial Troops were still seen as the law and were respected by the general populous of the galaxy. People still believed in the good of the Empire and that it would eventually beat the rebels. Even as the Empire lost battles people still flocked to join the Empire and fight for their beliefs. The Imperial Fleet was huge and could easily win any battle. Fear of the Emperor kept many of the members who thought of deserting in the Imperial Armed Forces and doing their job. The Imperial Armed Forces is at its peak and does whatever it wants to. Many of the members fear having to perform a bombardment against a populated planet but other than that they have no problems with their duties. The few who have found Imperial Service a problem and were looking for an alternative usually left for leave and never came back choosing to assist the rebels. The destruction of Alderaan caused many defections but the Imperial Armed Forces remained strong.
Warlords: During this time the Rebel Alliance has taken Coruscant and controls most of the galaxy and little chunks of it are controlled by former Imperials who have become Warlords. The Warlords usually have a system or two under their control and about five star destroyers. Most of the Warlords are content with defending their territory and building up their army at the present time. Members the Imperial Armed Forces generally stayed with their direct superior and went with whatever Warlord directed their commander. A few Warlords had large fleets and a capable fighting force. One of these was Zsinj who possessed the Super Star Destroyer Iron Fist and attempted to capture another Super Star Destroyer. A faction of the Imperial Command stayed together but acted like the Warlords and stayed in a defensive posture until Thrawn’s return.
Thrawn’s Return: During this time the Imperial Armed Forces have mostly gathered behind Grand Admiral Thrawn and his fleet. Thrawn returned from the outer rim and reinforced the Imperial Armed Forces. Thrawn represented a more official Imperial Force because he was officially made a Grand Admiral. Thrawn managed to push the New Republic to the brink of collapse using his great tactical genius. Thrawn was about to destroy a New Republic assault on Bilbringi until one of his former Noghri bodyguards assassinated him. The Imperial Fleet withdrew and went into hiding.
New Jedi Order: During this time the Imperials and New Republic have reached a tenuous peace agreement. Admiral Palleon is leading the Imperials at this time and provides a kinder face for the Imperials and is willing to work with the New Republic to accomplish what needs to be done. At the beginning of the war with the Yuzhaan Vong Palleon sent out a small attack force to assist the New Republic with the new threat but the Moff’s called for the ships to come back and prepare for their own defense against the Vong. Enrollment in the Imperial Forces is rising again and it is being seen as a legitimate government.
During the rebellion the Emperor served at the top of the command chain and every major decision had to be approved by him. Just below him were the Moffs and the Grand Admirals. The Moffs had control over their own section of the galaxy and controlled what went on in their. The Grand Admirals had fleets that would cross different Moffs sections but had no direct control over them. Underneath the Moffs were System governors who ruled a system of the Moff’s sector. The system governor would have separate planetary governments if the planets were large enough or important enough.
After the rebellion the Moffs took over control of their own forces but managed to hold together. The basis of the system stayed the same although the head had been killed.
During the warlords’ era many of the Moffs took control of their forces and declared themselves separate from the Empire. A strong chain of command existed elsewhere in the Empire.
During Thrawn’s return most of the Imperials gave him their full support and he became the leader of the Empire. Thrawn had direct control over the men under him. Thrawn used Joruus C’Baoth to give his men orders so he could subvert Thrawn’s will and give his men false orders.
During the New Jedi Era most of the warlords have been destroyed and the original system has been put back in place with Admiral Palleon at the head of the Empire.