I doubt that the people of South-East Asia will join the war because they lack good armies.
Southeast Asia is a peaceful region where there is no war, although they are truly militarily weak
Yes, if there's going to be a 3rd world war, it's only the Americans, Europeans and 2 Asian countries, China and Russia. If you're from South East Asia, just enjoy the market changes and keep an eye on it. Recently, there is a pump happened in the market and I think many investors from the SEA takes it as an opportunity. It is the advantage of certain countries that do not have too much power, far away from war. The whole world war 3 situation that is spreading in the internet is exaggerated and some of the people think it is very non-sense.