Revolutionary defeatism is a principle which only holds in the industrialized, imperialist West. By this I mean generally the axis aroud the alliance NATO.
Why is this so?
Revolutionary defeatism as a leninist tactic is only applicable during a conflict between imperialists (usually) about the redivision of the world and booty. It means that the duty of a communist/worker movement of a warring imperialist state is to sabotage, slow down and disrupt the state, and turn the imperialist war into civil war. This is what the Communards did. This is what the Bolsheviks did. This is a tactic that is only applicable in the core. It also extends under certain conditions to when an imperialist state is not waging a war of conquest on some other, non-imperialist nation. But in this case it is much more difficult to turn this war into a civil war.
Third worldism on the other hand thinks that imperialism has amassed such wealth from 'overexploitation' and 'uneven exchange' that it can afford to bribe their working class, create a massive middle class/labor aristocracy that has material interest tied together with imperialism and therefore will not struggle against it. Thus the revolutionary subject, if there is one, can only be from the imperialized periphery, the global south, third world.
There are some problems with accepting third worldism over revolutionary defeatism in the current context. By that I mean the developing war between the US and PRC (which has started last time Trump was in office with the then trade war and restarted now with the tarrif war). All wars start first as economic wars. All indicators are that, if the US does not have its perestroika and glasnost, there will be hot war.
Which of these tactics is then applicable in a hot war between China and America?
First of all, we must be clear that in no way can the PRC be regarded as an 'imperialist' power. Reasons for this are many, but I'll just link this video that I usually spam when dealing with leftcoms. So I want to make it very clear for anyone that has read up to this point:
a war between the US and PRC is not an interimperialist war. It is a war of American aggression to safeguard world imperialism.
https://www.youtube.com/watch?v=FHm9rsLIPjAPost too long. Click here to view the full text.