The third law of Newton assumes that forces are due to the interaction of two bodies. Of course, a particle can interact with several others. But the result of these interactions can always be broken down to interactions between pairs of particles. Is there in nature an interaction, say between three bodies, whose resultant force cannot be decomposed into the sum of forces between the pairs?
I guess that with the introduction of fields to remove the "spooky action at a distance" this problem is solved. But maybe there is some effective interaction for slowly moving particles that is of the form I'm looking for?