Explain how ISIS was defeated in Iraq and Syria by emphasizing the strategic role of the Islamic Republic of Iran

As an emerging phenomenon, ISIL was able to influence the region countries and the world in a short period of time, and as a very destructive actor, was able to occupy a large part of the territory of Iraq and Syria and to form a government based on the Islamic Caliphate. The actions of this Salafi-Takfiri group, while threatening the security and territorial integrity of Iraq and Syria, are a direct threat to the security of the Middle Eastern countries, especially the resistance axis countries in the region. Since Iran is one of the Middle East countries and the leader of the resistance axis in the region, the existence of ISIS in Syria and Iraq, in addition to the effects and consequences on the internal structure and security of these countries, is undoubtedly an objective threat to Iran's national security and territorial integrity. Therefore, Iran in alliance with the governments of Iraq and Syria, as well as with the effective help of Hezbollah in Lebanon and Russia, sought to strike and destroy ISIS.
Methodology
Given the theoretical nature of this study, it employs a qualitative-descriptive-analytic approach. In qualitative research design, data from historical, descriptive and empirical research are used. The data needed in this study are collected through library references, documents, and various internet websites and resources.
Results and discussion
Iraq was an occupied country that did not have an army to provide security, and more importantly, the process of power transfer in this country was slow, and with the intervention of regional and international actors, there was no consensus on government formation and the lack of security in a war-torn country provided a justification for the presence of foreign forces in a country (Cloud & Shanker, 2007: 26). Edward Snowden, a former US National Security Agency contractor, said: "The US, British and Israeli intelligence agencies were instrumental in the formation of the Islamic State of Iraq and the Syria (ISIS) group and in an operation called 'Bee's Nest' formed ISIS group.”(Khoramshad & ashna, 2018: 77). With the start of the Syrian crisis in the beginning of 2011 and the change in the nature of the protests from political and civil to terrorist and sectarian under the influence of media propaganda and psychological operations, several Salafi-Takfiri groups went to Syria to fight to Alawites. During the Syrian crisis, heavy and extensive psychological propaganda was carried out in order to induce the religious and sectarian nature of the Syrian war, and this propaganda and psychological operations caused a large number of Salafi of Sunnis to go to Syria to fight with the Alawites (Zarean, 2014: 27). The ISIS terrorist group was once present in Iraq and Syria and had occupied large parts of northern Syria and Iraq. This terrorist group is currently active in parts of Libya and Nigeria, Afghanistan and Southeast Asia. Many areas under ISIL control have now been liberated and possessed to the Iraqi and Syrian governments. The activities of the Takfiris do not endanger the borders of the Islamic Republic of Iran; But Iran's security should not be sought within its borders. The front line of the fight against ISIS and its supporters is not limited to the borders of Iran, and today Iran, as the most powerful country in the region, has expanded its strategic depth to the southern borders of Lebanon with the Zionist regime. ISIL's view of the Shiites, shows that this group is targeting Iran as the core of the Shiites and believes that their group should move toward the core. Considering that the presence and activity of the ISIS terrorist group in Iraq and Syria became a threat to Iran's national security; therefore, the Islamic Republic of Iran seeks to eliminate security threats caused by the crisis in its two necessary and unnecessary security circles, namely Iraq and Syria, and by adopting a defensive approach, it takes steps to achieve its goals and interests, especially its security interests and resistance members. In fact, Iran has played the most important and effective role in destroying ISIS in Syria and Iraq. Undoubtedly; this role will intensify the hatred of the Americans and its regional allies, especially Saudi Arabia and the Zionist regime, towards Iran now and in the post-ISIS era, and consequently will design new strategies to confront Iran, which is the leader of the resistance axis in the region. The martyrdom of Sardar Soleimani and Abu Mahdi al-Mohandes, the deputy commander of the Iraqi Hashad al-Shaabi forces, and their companions on January 3, 2020, near Baghdad International Airport by US drones on Trump's direct orders can be analyzed in this regard. Meanwhile, in response to these attacks, the Islamic Republic of Iran also fired a missile at the Ain al-Assad base in Iraq's Anbar province and a base in Erbil, where US forces were stationed, on January 8, 2020.
Conclusion
With anti-Shiite slogans and actions, the ISIS terrorist group is practically in line with the goals and interests of the actors opposed to the resistance axis and at the head of it, is the Islamic Republic of Iran, which wants to weaken the axis of resistance and reduce the regional influence of Iran. ISIL can be considered a threat to Iran's territorial integrity, because ISIL is thinking of creating a caliphate, and the establishment of a caliphate requires the integration of the countries of the region into one country. Therefore, the Islamic Republic of Iran, by adopting military and diplomatic measures, defeated the goals of this terrorist group and announced the end of the self-proclaimed government of ISIL. The costs and consequences of the actions of the ISIS terrorist group in Iraq and Syria, which have also been very heavy, have disrupted the development process of these countries and added to the increasing complexity of the political crisis in Syria and Iraq.