  We consider the entropy production of a strongly coupled bipartite system.
The total entropy production can be partitioned into various components, which
we use to define local versions of the Second Law that are valid without the
usual idealization of weak coupling. The key insight is that causal
intervention offers a way to identify those parts of the entropy production
that result from feedback between the sub-systems. From this the central
relations describing the thermodynamics of strongly coupled systems follow in a
few lines.
