"Attack line" refers to a line of action or argument that is intended to criticize, challenge, or defeat someone or something. It is a strategy or approach used to aggressively go against an opponent or a problem. Full definition
If the chronic inflammation attacks the lining of the arteries, you get heart disease. (naturalmedicine101.com)
He simply seemed to look like he would never be that man you had complete confidence of being able to lead the Arsenal attack line. (justarsenal.com)
After all, any good media strategist knows that attack lines need to be formulated early and repeated endlessly if they are to have any traction. (totalpolitics.com)