Final answer:
Switzerland did not hold colonial possessions in Southeast Asia, unlike other European powers such as Portugal, Spain, the Netherlands, France, and Britain.
Step-by-step explanation:
The European power that has NOT held colonial possessions in Southeast Asia is a. Switzerland. Historically, other European powers such as Portugal, Spain, and later the Netherlands, France, and Britain played significant roles in the colonization of Southeast Asia, which included areas like present-day Vietnam, Indonesia, Malaysia, and the Philippines.
For example, Portugal initiated the era of Atlantic exploration and also established control over the city of Malacca in 1511, but they were later expelled. Spain took control of the Philippines, and the Dutch, who focused on trade over missions, became a major force in Indonesia. The French and the British colonized mainland regions of Southeast Asia, with Burma under British colonial rule and other parts under French rule.
Switzerland, being a landlocked country with a tradition of neutrality, did not engage in the same colonial endeavors as its European counterparts.