Because the situations or relationships concerned [in private international law, whatever its name may suggest] are by definition inter-jurisdictional, the machinery of each legal system necessarily interacts with the machinery of other systems. Sometimes the gears mesh, sometimes they clash. …
The overall picture is thus of a complex arrangement of complex mechanisms, interacting in complexity but not always in harmony.
This is clearly an area in which it behoves the Court to tread softly, and with care. But just because it must tread softly, that does not mean that it must fear to tread at all.
From the Opinion of Advocate General Eleanor V. E. Sharpston in the Case of Grunkin and Paul, Case C 353/06