Otherwise it will be smaller countries getting into battles they never asked for under the hidden influence/help of either US or China and I don't think any sovereign country would want to be at the mercy of either of these powers playing puppet show by making all countries their puppets until they either be colony of either of the countries/sides. Either other countries rise up in coalition and reject both powers or create one world multilayer governance and solve war situations forever so that smaller countries are saved and are independent.
If there's no one world government then there will be constant non stop wars after wars. Either we can repeat what humans did in every civilization before or we can have a consensual democratic/socialist/multilayer governance that works human centric with no leaders/elites, individuals get the control to decide the governance/services/create their world of course with guided rules and regulations that's common for all. Once we choose to isolate then there's no going back.
Because if we don't do this now unlike other civilizations in the past we have other entities waiting for us to replace humans. Either we save humanity or sell/replace ourselves eventually as we disintegrated.
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