Afghanistan is located in a region that from a political, security, economic, cultural and geopolitical point of view, can be placed in a sub-class of a multi-regional system which includes Central Asia, Middle East, and South Asia. However, this country can mainly be considered a sub-class of the Central Asian region. Although the intense rivalry existing between India and Pakistan, has led Kabul to enter the regional equations in South Asia. On the other hand, Afghanistan is India's gateway to Central Asia, and the Middle East. Thus, India will be able to expand its strategic depth to Central Asia, and prevent itself from being surrounded by China and Pakistan. The result of the above mentioned issues, in addition of adding Afghanistan to the South Asian security concerns, is highlighting the position of Kabul in India's foreign policy. In this paper, we seek to answer the following questions with the use of Buzan security complex theory. "What is Afghanistan's place in India's foreign policy concerning South Asia after the events of Sept. 11, 2001? What are the factors affecting Afghanistan's entry into the security dynamics of South Asia?" The authors' hypothesis is as follows: "Afghanistan is a country that acts as insulation between several regional sub-systems Political, economic and especially the security crisis following the developments after September eleven, 2001 have pushed this country towards South Asia. India's foreign policy also seeks to exploit these new conditions."