Political officers were usually a specific group within the officer corps of the Red Army and armies of the Warsaw Pact. Theoretically, the term is synonymous with that of the 'political commissar', although 'officer' is used as more precise general term, as the term 'commissar' changed its meaning over time and was generally not used in other Warsaw Pact countries.

The institution of the military commissars has been created after the February Revolution by the decree of the Provisional Government no. 132 from 13th July (30th June O.C.) 1917, as an attempt to monitor the loyalty of the officers. This solution was then adopted by the communists who overthrew the government in the October Revolution later that year. The first political military organization was the All-Russian Bureau of Military Commissars formed on 6th April (24th March O.C.) 1918, with the commissars designed to become the 'direct representatives of the communist government within the military structures'. They were assigned to their military counterparts in the officer corps. Soon after, in the November of 1919, the Revolutionary War Council of the Republic created the lower echelons of the political officers, operating on the company and platoon level.

The power structure in USSR is sometimes likened to a form of an organizational triumvirate composed of CPSU, military and secret service (Cheka-OGPU-NKVD-KGB etc.), with each two members counterbalancing the attempt to seize the power by the third. Initially, political officers, performed a role similar to the commissars of 18th and 19th centuries, who were tasked with ascertaining loyalty of mercenaries and troops fighting in the civil or revolutionary wars (e.g. War of American Independence). They also had very wide prerogatives and although they were officially considered 'consultants' delegated by the party to consult commanding officers in the matters related to the Party orders and political matters, in reality they were also looking for signs of subversion and lack of loyalty. This was considered necessary, as many of the Soviet soldiers were former officers of cadets in the pre-revolutionary Imperial Army and their loyalty to the communist cause was not considered a given. After deciding that the commander of the unit political officer was attached to is disloyal, the latter had the power to relieve the commander from his position (arresting him, if necessary) and temporarily take command of the unit until the replacement arrived. This could and did led to many problems, as early political officers were primarily Party members and even if they happened to be well-versed in political matters, they usually had little military experience not to mention any commanding skills, so clashes of interests were not uncommon. On the other hand, according to Lev Trotsky, commissars bore the responsibility of the success of their units and in case of retreat or similar failure, commissars were to be executed first.

After the victory in the Russian Civil War and defeat in the Polish Bolshevik War, the military situation in USSR stabilized. Since the 1925 the role of political officers begun to shift from the earlier commissars to a strictly political consultants and morale officers, commonly called 'assistants for political, educational and instructional work' (rus. помощник по политико-просветительской и воспитательной работе, usually shortened to помполит/pompolit). Although higher ranks of these officers usually included the word 'commissar' (from the 'brigade commissar', equivalent to Major in the Army or Captain 3rd Class in the Navy), their privileges were a far cry from the commissars of the 1920s. Their main duties were thus limited to the political work (maintaining political awareness, instilling patriotic attitudes, counteracting enemy propaganda) and generally assessing and improving morale whenever possible. It was also a common practice to not assign a political consultants to commanding officer who were members of the Communist Party themselves.

This situation changed again in 1937. In the wake of the increased opposition to the party within the military and increased contacts between Marshall Mikhail Tukhachevsky and the Western politicians, the Central Executive Committee and the Council of the People Commissars decided to revive the institution of the war commissars. The order no. 0178 issued by National Commissariat of Defense reconstituted commissars, giving them prerogatives similar to the ones enjoyed by them during the Civil War and early 1920s. This is generally considered a part of the Great Purge of the 1937-1938 and an attempt to strengthen Party's grip over the army. This solution was in force when the Second World War broke out and when the German army invaded USSR in 1941.

Actual war quickly shown, however, that the highly influential political officers with high commanding prerogatives but little or none military experience do more harm than good, especially after the initial German victories, and thus, by the order of the Supreme Soviet issued on 9th October 1942, war commissars ceased to exist and were once again reduced to strictly political work, as deputy commanders for political, educational and instructional work (rus. заместитель командира по политико-просветительской и воспитательной работе, commonly shortened to замполит/zampolit).

In general, political officers were not involved in politics of any kind, and they were primarily responsible for the political formation of soldiers (hence the name), upholding morale and administrative duties. Political officers were usually tasked with various activities related to political awareness and patriotic attitude of the soldiers, from the control of the internal bulletins, to lectures about the actual political events and the role of the military in the world and the awareness of the Party policy and tenets of Marxism among the enlisted men. They were also responsible for preparing and conducting courses related to military doctrine, history, ethics, politics, military law and similar topics that were curriculum of the courses for officers and NCOs). They were also responsible for teaching unit commanders in performing similar lectures with rank and file soldiers.

By extension, political officers were also acting as a kind of censors (gatekeepers if you will) that were approving books to be included in the libraries and movies to be screened for the soldiers, to make sure their content is appropriate for the morale and not subversive in any way. As mentioned before, some political political officers were also delegated to perform administrative duties, usually related to the social matters, such as the fair treatment of the soldiers, as each enlisted man could have report undesirable events (e.g. hazing) to any political officers, circumventing his immediate superior or the unit commander. Additionally, such officers were often tasked with the tasks related to the families of the soldiers, such as payment of the military benefits or assigning housing for the soldiers' families, disabled, veterans etc. Some of them were also acting as liaisons between the the military and civilian organizations.

Summing it up, save for the period of the Russian Civil War, Great Purge and the first year of the Great Patriotic War, political officers in USSR, as well the Warsaw Pact countries (after the war ended) were merging the duties of political instructors, morale officers and psy-ops.