Final answer:
The Mongols did not conquer India due to the Himalayas, the hot and humid climate, the strong Delhi Sultanate, and their difficulties in naval warfare and maintaining control over new regions. Decentralized resistance in India and adverse effects like disease on their armies also played roles in limiting Mongol expansion in India.
Step-by-step explanation:
The geographic reason that likely explains why the Mongols did not conquer India pertains to a combination of factors, including the challenging terrain of the Himalayas, the climate, and the strong resistance put up by the Delhi Sultanate. The Himalayas presented a formidable natural barrier that made large-scale invasions difficult. Additionally, the hot and humid climate of the Indian subcontinent was hostile to the Mongol cavalry accustomed to the cold steppes of Central Asia. However, the Delhi Sultanate played a significant role in repelling the Mongols, as it was in a rare period of unity and strength during their attempts at invasion.
Despite the Mongols' expertise in warfare, including siege tactics, there were also other regions that they found difficult to conquer, such as Southeast Asia and areas requiring naval warfare, which was not their forte. Furthermore, the Mongols faced difficulties in maintaining control and extracting wealth from already-conquered territories, which could have influenced their decision not to extend their empire into India. Meanwhile, diseases and epidemics caused by the foreign climate also posed challenges to the Mongol armies, as noted in the debates of the Mongol court.
The Indian subcontinent's ability to resist the Mongols, unlike the more centralized states such as China under the Song dynasty, also likely benefited from its decentralized structure during the eighth through tenth centuries. This allowed for more localized resistance and less of a singular, centralized target for invading forces.