In political literature, there are different definition for political legitimacy such as being legal, in accordance with the law or in accordance with contentment of people.  In general, the term legitimacy is used to describe the legality or validity of political power which originates from ruling law, individual charisma or social traditions. According to Max Weber, legitimacy is based on “public belief” and in exchange it requires people to obey. So, when a political regime is legitimate, its participants have certain beliefs and inner satisfaction to willingly obey the regime. In addition, a legitimate government is always accountable and answerable to its all citizens. In fact, it is responsible against all decisions it makes on behalf of its citizens and regularly explain their decisions and actions to the citizens through various channels.
According to Max Weber, there are three types of legitimacy: traditional, charismatic, and rational-legal: traditional legitimacy derives from societal custom and habit that emphasize in history of the authority of tradition. Charismatic legitimacy refers to acceptance of enigmatic leader but it is relatively unstable because the authority held by a charismatic leader may not easily extend to anyone else after the leader dies. The most modern type of legitimacy is rational or legal legitimacy which links to the level of conformity with to public opinion and rule of law. If we want to combine all three elements in one world, we can summarize that legitimacy is synonymous to public satisfaction. So, the core origin of legitimacy is people’s satisfaction. Sometimes people are unsatisfied from the ruling government. So, the question is what factors are behind public dissatisfactions? In other word, what are the theoretical factors of legitimacy crisis? How can we prevent form legitimacy crisis?
In response to these questions, there are several theories which altogether explain the cause of legitimacy crisis. The first theory is psychological theory which is linked to human deprivation. Human deprivation itself is divided to three categories: decrimental deprivation, aspirational deprivation and progressive deprivation. In decrimental deprivation, the human expectation is stable but its political and economic abilities are decreased and so they get unsatisfied. In aspirational deprivation, the human expectations are increased but their abilities are stable. In progressive deprivation, the human expectations are increased but their abilities are decreased. According to political theorists, all three cases can cause political riots  and insurgencies while the third case is more threatening  and more applicable in Afghanistan. Given the level of freedom and educational growth in last two decades, the expectation of citizens has increased but their financial and political abilities are decreased.
The second theory which explains the level of political legitimacy is sociological factor. This theory is based on functionality and accountability of the ruling system. According to this theory, the people support political system as long as it ensures social and economical orders and fulfill their needs. It means, as soon as the political system loses its functionality or accountability, it will also lose its legitimacy. As the level of illegitimacy depends on level of public dissatisfaction, it will intensify when the elites of the ruling system shows more obstinacy against public will and demand. If we look at most of social uprising, it is largely rooted in public dissatisfaction combined with obstinacy of the ruling government. Therefore, the people will not only disobey that government but also stand against.
The next illegitimacy factor is power sharing conflicts. The power sharing conflicts happens when a group or groups of political people try to have monopolistic domination on a country. These kinds of political trend will not only cause public dissatisfaction but also identity and security crises.  In this case, the political conflicts intensify when the political factors combined with sociological and psychological factors. In the other word, if the government could not provide equal opportunities among citizens and if it could not fulfill the social and economical demand of the people, they will get angry and may join the opposition groups or establish new opposing groups. Thus, the ruling system will face more political challenges when it loses balance of political power. The balance of political power between/amongst various groups can cause civil war but imbalance of power will pave the way for domination of powerful group. In such cases, the opposing groups will show more bravery to lunch political maneuver and attract more people for the purpose of reaching power or checkmate the political rivals. Nevertheless, the domination of powerful group will not lead to political stability, because still there is a hidden or unhidden potential to challenge the government.
The last cause of illegitimacy crisis is ideological factor. Based on ideological factor, when the people of certain faith feel that their faith and religious values are under threat or aggression of the ruling system, they will use any tools to overthrow the ruling system. This factor is more rampant in traditional or religious societies such as Afghanistan. If we look at history of Afghanistan, there was many riots and religious uprising because of violating religious values. For example, the government of Amnullah Khan was shortly toppled due to the same factors even though he had a high reputation in Afghanistan because of his role in independence of the country. 
This factor may or may not links with other factors and so sometimes people riot even if they have no economic or political problems. This factor will get more powerful when all the religious groups including religious scholars reach a consensus against ruling system and then, no power would be able to control the people. If we look at the recent history of Afghanistan, this consensus was created against Soviet Union aggression in the country. From one hand Soviet Union forces overtly showed their hostility to religious values of the country, on the other hand, all people were confident about legitimacy of Jehad against the aggressive power.