1. Only Malaya was an independent nation while Singapore, Brunei, Sabah and Sarawak were still under British control. These territories were considered too small to be independent entities. It was felt that a merger with Malaya would bring early independence to these territories.
2. The British were agreeable to a merger of these territories and granting independence as there were many similarities between Malaya, Singapore, Sabah, Sarawak and Brunei, in terms of the legal system, economy, history, financial structure and people.
3. Political uncertainty in Singapore with the Socialist Front posing serious challenge to PAP’s dominance. The governments of Malaya and Britain were not in favour of the socialist forces winning in the elections and taking over Singapore’s administration.
4. Rising communist threat in these territories. There was a greater danger for Malaya and Singapore if the communists in these places join forces. By merging and granting independence to these territories, the communists could be easily defeated.
5. The British were confident their economic and social interests in these territories would be protected with the merger and independence of these territories.
6. Alliance government in Malaya realized merger must not be only with Singapore because the ethnic balance will change with Malays losing the majority. The merger proposal was to also bring in Sabah, Sarawak and Brunei to protect the indigenous people, preserve the ethnic balance and maintain their majority.
7. Sharing of economic recourses for mutual benefit. Through merger, these member states will have better economic and trade cooperation which was expected to benefit all. In particular, it was expected to bring progress to the economically less developed Sabah and Sarawak.
8. Common stand in foreign policy and international relations.
9. Other events before the formation of Malaysia.