Jawaban:

The Dutch were able to make good headway in Java and Sumatra mainly due to their superior military technology and organization, as well as their ability to exploit local political rivalries and economic interests.

Here are the logical reasons are:

• The Netherlands had a powerful trading company, the Vereenigde Oostindische Compagnie (VOC) or Dutch East India Company, which established its headquarters in Batavia (now Jakarta) in 1619.
• The Dutch used the rivalries between local kingdoms in Java and Sumatra to expand their influence through treaties that favoured the Dutch.
• The Dutch used military force to subdue indigenous rebellions, such as the Padri War (1821-38) in Sumatra and the Java War (1825-30) in Java.
• The Dutch changed the political and economic systems in Java and Sumatra to favour their colonial interests, such as the cultuurstelsel system that required farmers to grow cash crops for export.