Answer and Explanation:
Nomadic empires could not retain for too long. These empires remain short-lived wherever they emerged. Their whole culture used to revolve around threatening others and herding from place to place. Genghis khan tried to arrest most nomadic groups, but they emerged from somewhere else as a centrifugal force.
The Mongols have no cultural and social infrastructure to sustain their power. Railways and rifles allowed people to invade and to penetrate other places more remotely.
The decline of Nomadic empires, especially of Mongols, was happened because of three primary reasons:
1. Natural phenomena:
People were not able to survive in epidemics. Climate change left them merciless.
2. Foreign Policies:
Invasion of enemies, the crisis of civilization, and cessation of outer incomes also become the reason for their downfall.
3.Internal causes:
The lack of unity led them toward separatism, weak infrastructure, class struggle, civil wars, and the coming of political rulers without any vision and intellect also become a reason for their decline.