My French teacher said South-East Asia (Combodia, Vietnam, Laos) speak french. How did they learn french?

How come East -Asia (China, Korea, Japan) doesnt speak french?

of consisting teaching, and to some level of fluency, even if sparse? Plus, without actually being in the country that is..
Mind I am Portuguese, and am fluent in other languages like English, French and Spanish, but never had any direct contact with any South East Asian language, and will have only 1 year to learn Vietnamese before I can actually make it there for another full year. I'm just wondering whether it could be any possible for that to happen or whether I am just being naive to think that I might actually be able to reach any level of fluency without being actually being there!
Opinions? lol

Thank you.
@ 1st person: Well History, together with present day papers and reports, tell me that only the elderly speak French still... it's the ex colonizer's language, the youngsters wont be all that familiarized with it anymore, I should think! Or am I wrong about that? Because it sure would help if they did speak French, but then again wanting them to do so would just be neo-colonialist of me! And I will have to be talking to people of all ages.. and interviewing them even if I can... wonder whether the youngsters speak English.. but then again speaking in Vietnamese if I could would just be a lot more fair on the locals. I’ll see what can be done until then I guess...
@Jerry N: But why is it that learning the language wouldn't help? You missed me there? What's your point?
And how can Vietnamese be based on Portuguese sounds? It's been a long time since the Portuguese sailed through the coasts of south East Asia... a few centuries to be more precise, and when they arrived to the place the locals already had their own languages, Mon-Khmer based languages... from the mon-khmer family!!! I have to say mate you have totally lost me on your comment! Anyway, if you can, explain further, tk u!

i'm an englishman living in melbourne, australia with 6 months left on my working holiday visa and want to train and qualify to teach english as a foreign language in South East Asia, but i have no idea where to start... i just want to speak to someone who can point me in the right direction...
anyone know? i don't have a degree, can i still do it?

I feel shamed to ask "Do you know Thailand ?" I am Thai. I found that Vietnamese and Indonesia language are available in Google translation machine but Thai. I think in South East Asia several countries such as Laos Cambodia Singapore Myanmar Vietnam Malaysia and China support studying Thai language. However, There are not much programs to promote study Thai or other applications for instance translation, dictionary, reading machine or OCR.
When I register the websites, they want me to inform the language but there is no Thai provided. What happened? Maybe my language is a minority of world language use.