I will suggest that you think about it before calling the US
influence in SEA "sucks".
After WW2 and the Japanese defeat, Nationalism and Idealogies such
as Communism were high on the people's minds. The former Empires,
Britain and France, was exhausted and no longer had the power to
fight the various problems of running a colony.
The Soviet Union and Communism were spreading fast in both Europe
and Asia, with half of China already in CCP's control by the end of
WW2. Ho Chi Minh was waging a war for independence in Vietnam,
using a Socialist Model. So is Gandhi and his Indian Congress
Party.
The US (and I would speculate, UK, France and Australia) feared the
rise of Communism in the colonies (or soon to be ex-colonies as
most were given independence) and thus the US strengthened ties
with Thailand. As history played out, Thailand proved to be an
important ally to the US in the Vietnam War, serving as a supply
base and R&R for the troops.
If the US had not involved itself in SEA, then the very place we
are living in now will be totally different. Would we be better of
or worse of? If we speak in economic terms, then there is a high
chance after the initial 10-20 years of growth, income and GDP
growth will stagnate (like what happened with the USSR) and
eventually the Socialist Model may fail. We might be experiencing
similar results to the Eastern Bloc of Europe in 1990, when the
USSR slowly disintegrated and the countries left to fend for
themselves.