If we are fallible and not omniscient, surely it is exaggerating to say it is always possible to solve problems without coercion?
‘Problems are soluble’ does not mean that knowledge can be created by fiat, or that anyone who fails to interact entirely non-coercively is evil. That is horribly far from how I see it. Solutions are sometimes hard to come by. It is often not obvious how to solve a problem. Truth is not manifest.