Adam Clarke on Deuteronomy 28:52

He - Nebuchadnezzar first, (2Kgs 25:1, 2Kgs 25:2, etc)., and Titus next; shall besiege thee - beset thee round on every side, and cast a trench around thee: viz., lines of circumvallation, as our Lord predicted; (see Mat 24:1, etc., and Luk 21:5, etc.); in all thy gates throughout all thy land - all thy fenced cities, which points out that their subjugation should be complete, as both Jerusalem and all their fortified places should be taken. This was done literally by Nebuchadnezzar and the Romans.