Final answer:
The Mongol invasions led to Japan's increased isolation, a distinct internal development, and a strengthened belief in divine protection. It also helped shape Japan's future military strategies and expansionism.
Step-by-step explanation:
The long-term consequence of the Mongol invasions on Japan was multifaceted, but chiefly it led to Japan's increased isolation and a turn inward for self-reliance. The repeated failures of the Mongol invasions, including the incidents in 1274 and 1281 where storms destroyed the Mongol fleets, reinforced Japan's decision to cut off formal ties with the aggressive and expansionist Mongol rule in China. This self-imposed isolation spurred an internal development that was distinctly Japanese, as the country adapted Chinese cultural aspects to fit its unique context. Notably, the belief in divine winds, or kamikaze, that protected Japan became embedded in the culture, symbolizing a protective force for the nation. Moreover, the threat from the Mongols led to increased fortifications and military preparedness, which would influence Japan's future military policies and expansionist activities, as witnessed in their later invasions in Korea and northern China's territory of Manchuria.