During the 1500s and 1600s european were able to take control of the international trade from Asia diverting the profits. As a result of this the europeans countries became stronger and weakening the asian empires . By the 19th century Europe was in a position such as to stablish its authority over Asia, specially on the indian subcontinent and southeast Asia.
Six countries held the power throughout the region, this countries were:
Portugal: They had the least impact in the region, they captured Malacca in 1511 but lost it by the hands of the Dutch on 1641 maintaining only a small piece of territory in the island of Timor.
Spain: They ruled the Philippines and Manila since 1571 untill 1898 when they were defeated in the Spanish-american war
Netherlands: They had two periods, the first one was more concern about maximize the profits through trading monopolies. While the second period was more interested in territorial administration and began after the Napoleonic wars on 1825 and ended up in the 1930s with the end of the Second World War.
Great Britain: They conquered Burma and attached it to the Britih India loosing this way their ethnic identity
France: They conquest the so called Indochina on 1907 previous captured of Vietnam 50 years before that
United States: They held the colonialism on the Pihilippines as a result of the peace settlement with Spain after their war on 1898
The only nation from southeast Asia that maintain its independence during the colonial period was Thailand previously known as Siam and the most commonly cited reason by historians is that the rulers of there gave concessions to the western countries, mostly about trade.
It would be the "joint occupation" policy that allowed people from both Britain and the United States to settle in Oregon country, since this was thought to be the most economically advantageous for the region.
