Not really imo, a sudden collapse of america would create chaotic power vacuums but they mostly be internally localized to america and countries completely dominated by america. Countries on the periphery would not immediately jump to fill the power vacuum molded to a white-supremacist settler-colonial hegemon as they do not have the material basis to fill such a role.

Furthermore, such a framing takes for granted that the current world is run by an orderly, functional system made up of countries subservient to a hegemon when in fact, the current situation is quite chaotic, as we live in “interesting times”. It is moreso a complex, multipolar situation made up of blocs with competing interests, and its just that one bloc mainly headed by one country is getting its way. Unfortunately, this country is america, with an agenda fundamentally inseparable with the extraction and genocide of other civilized nations. Other blocs do have their own interests, but it is unlikely they would be as bloodthirsty as america.

Moreover, even if things somehow do lead to war, historically, during the time of chaos highlighted earlier, one of the greatest socialist experiments, the USSR, was born. And for a time, there was hope for a better future in the world.

At the end of the day the preparedness and struggle of socialist movements worldwide will decide what will happen if such a situation occurs.