How might the seas east of china act as barriers to trade and travel?

The seas east of China, particularly the East China Sea and the South China Sea, can act as barriers to trade and travel due to their challenging navigation conditions, including rough waters and unpredictable weather patterns. Additionally, geopolitical tensions and territorial disputes in these waters can lead to increased military presence and restrictions on maritime traffic. Moreover, the region's complex network of islands and reefs can complicate shipping routes, making navigation more difficult and potentially dangerous. These factors can ultimately hinder the efficiency and safety of maritime trade and travel.