Extended Abstract
Introduction
With the increase in the threat of terrorism after September 11, the issue of terrorism became the first concern of the American security and defense strategy. This led to the United States sending its military forces to the West Asian region for this purpose, and from that year until now, it has been involved in the fight against terrorism. However, America's approach in the field of fighting terrorism has not always been stable and has undergone changes and transformations, the reduction of military forces or their withdrawal from Afghanistan can be examples of this transformation.
Threat Perception level causes to the adoption of an approach, appropriate to the level and type of the threat by different countries and actors. In this regard, US did increase the priority of terrorism threat but as time went on, after 2016 and with the new emphasis on great power competition, the threat posed by state actors are again at the top of the list. This can also be seen in US military withdrawal from Afghanistan.
In this regard, the current research seeks to answer the questions; firstly, to what extent has the importance of the threat of terrorism changed in US? Secondly, how has the aforementioned change affected the US strategy to fight terrorism? The hypothesis is that the importance and priority of the threat of terrorism has decreased and it is no longer at the top of the country's security threats and the priority of its action. This understanding has led US to reduce direct military presence, emphasize more on technology, adopt offshore balancing strategy, and emphasize more on empowering and using the capacity of partners and allies.
In order to investigate the issue and hypothesis, the article first examines the change in the threat of terrorism in American documents. After that, the causes of this change have been discussed and then attention has been paid to the change of strategy according to the change in the level of threat and the elements of the current approach in the fight against terrorism.
Research Questions
In this regard, the current research seeks to answer the question; How the changing priritization of the threat of terrorism has impacted US counter-terrorism strategy? The hypothesis is that the importance and priority of the threat of terrorism has decreased and it is no longer at the top of the country's security threats and the priority of its action; which leds US to reduce direct military presence, emphasize more on technology, adopt offshore balancing strategy, and emphasize more on empowering and using the capacity of partners and allies.
Methodology
Present article uses analytical-descriptive method combined with content analysis and library-based data collection to investigate the change in threat perception and the relationship between the mentioned perception with US counterterrorism strategy.
 
Conclusion
It is concluded that while reducing the threat of terrorism, the United States has changed its intention to eradicate terrorism and is now seeking to curb and manage it and learn how to live with it. According to the assessment of its own strength and that of its enemies, the United States has come to the conclusion that in the current era, state actors (especially China) pose a greater threat than non-state actors, and the threat of terrorism though it is serious, but not a vital threat against US interest. In other words, although there is still an incentive among terrorists to strike and attack America, they do not have the ability to do so. It is also found out that in US point of view, terrorism is no longer concentrated in the West Asia region and has spread geographically and has gained a strong presence in different regions of the world, especially in Africa.
Therefore, US made changes in its military strategy and the type of confrontation with terrorism. As a result, the United States completely withdrew its military forces from Afghanistan. We have also seen some transfers of troops and equipment at the regional level. On the other hand, we are witnessing the increasing presence of technological elements such as drones in the region and increasing their role in carrying out American military operations. This is also the proof and evidence of changes in US military strategies and tactics.
The most important elements of current counterterrorism strategy include strengthening light footprint approach, strengthening multilateralism and diplomacy, increasing the role of technology and networking systems and information, preventing access to a safe haven for training, and intensifying the use of offshore balancing and over the horizon strategy, training/equipping and enabling partners and allies, armed surveillance program, extending and deepening security cooperation.