In Southeast Asia the process of decolonization intertwined with superpower rivalry in particularly deadly ways. Beginning with the British counter-insurgency in Malaya, to the US wars in Vietnam and Cambodia, and ending in 1979 with the Sino-Vietnamese war, Southeast Asia would command American attention like no other region. However, after America’s humiliating withdrawal from the region, it would cease to play a central role in Cold War politics.
Time: Mid War
The main contested countries in the Early War are Burma, Laos/Cambodia, Indonesia, and Thailand. The USSR almost always ends up with control of Vietnam, while the US almost always has 1 in Malaysia and 1 in the Philippines by the end of the Early War, leaving the USSR loath to fight for either. By the Mid War, Burma will be sewn up, and then it’s a fight for the 1-stability countries, and of course, Thailand, a 4VP swing.
Since Asia is probably the most fought-over region in the Early War, Southeast Asia can’t help but get dragged into the fight. Thailand is obviously of critical importance, but both sides also have an interest in taking Laos/Cambodia (limit access from Southeast Asia into western Asia) and Burma (ditto, plus Indo-Pakistani War modifiers). Malaysia is not frequently contested, since it’s more of a stepping stone to Thailand, nor are the Philippines, but Indonesia often gets a little visit from Decolonization.
Occasionally, you will see an Early War Asia fight that boils down to total country count, and here you’ll see one side (usually the US) down battlegrounds but able to deny Domination by controlling lots of Southeast Asia countries.
The battle for Southeast Asia is usually already decided in the Early War. As the USSR, try to play Southeast Asia Scoring before the US can spare Ops to secure Malaysia and the Philippines.
The main fight will be over Thailand, easily the most valuable country, amplified by the fact that this will also affect Asia Scoring as a whole. Expect Brush War, ABM Treaty (if used at DEFCON 3), the China Card, and Ussuri River Skirmish to all play a role in deciding Thailand’s fate.
No Late War event explicitly targets Southeast Asia, and more to the point, Southeast Asia Scoring is usually no longer in the deck.