In other words they provided the political, legal and physical infrastructure by which the Mediterranean and its hinterlands were furnished with a common meta-culture, bringing both subjectively good and bad elements, and laying the groundwork for the very idea of a universal empire that would inspire future generations?
Yeah, I'll go with that.
I'd only add "economic" to the list of infrastructures. Wherever the Romans went in the West, they founded cities and an urban economies linked to the greater Mediterranean.
Good point. Heck, the forts/settlements they founded became the great cities of Medieval Europe, a contribution in their own right.