I just noticed a sentence in an academic paper which says:
This symposium has marshaled numerous insights regarding the emergence of a general field of inquiry within international law on the movement of people. To move into this conceptual terrain has required a certain amount of defiance of the conventional wisdom that questions of migration are within the purview of the sovereign state, and a matter of sovereign territorial prerogative.
But, this structure sounds somewhat weird to my non-native ears. If I wanted to write this sentence, I would start by "moving", not "to move".
Anyway, is the original sentence grammatically correct? (if yes, why?) What about starting with "moving"?