一体 => …the heck; …in the world; …on earth N3
に先立って => before; prior to ~ N2
に[先立「さきだ」]って/に[先立「さきだ」]ち/に[先立「さきだ」]つ => Before A occurs/takes place N2
Time, Situation
も構わず => without caring; without worrying about ~ N2
も[構「かま」]わず => Without considering A N2
Considering, Concerning