Not sure exactly how it caused conflict, but I know why it caused cooperation.
Explanation:
This allowed them to have the opportunity to monopolize the east/west trade using the silk roads. This helped connect eastern regions of Asia together.
Therefore, one would say that Islam arrived in South-East Asia in a peaceful way through trade and interactions between Muslim merchants and the locals. Similarly to Buddhism, Islam blended with existing cultural and religious influences of the Southeast Asian regions.
