Final answer:
Singapore is likely the Southeast Asian country most receptive to western influences, with colonial history, English proficiency, and western-aligned economic policies contributing to its westernization.
Step-by-step explanation:
The country in Southeast Asia that has been most receptive to western influences is arguably Singapore. As a former British colony, Singapore absorbed significant western influence during its colonial period, influencing its legal, political, and educational systems. Its strategic position as a major global trading hub also fostered a climate of openness to global and thus, western influences. Furthermore, Singapore's economic policies have been greatly aligned with western capitalist models, and the country is highly proficient in English, which is used as the primary language of business and government.
Other Southeast Asian countries have also experienced western influence, such as the Philippines, with strong historical ties to the United States and a large English-speaking population. However, Singapore's level of westernization in various aspects of society, from its governance and law to its lifestyle and commerce, is exceptional in the region.