When things start passing into the realm of war, legalisms go out the window. When we bombed Dresden and Tokyo, and nuked Hiroshima and Nagasaki, we didn't argu in court that the residents thereof were criminals worthy of capital punishment. Once we are in a war mentality, then any person or thing which is an asset to the enemy's war-making capability becomes a legitimate target
We didn't need to because we were not assassinating all those people individually for supporting non-state actors our government identified as terrorist organizations, we were killing them wholesale to break the enemy's will to resist. Dresden, Tokyo, Hiroshima and Nagasaki were enemy cities in nation-states with which our nation-state was formally at war. Total war between First World Industrial Age viable nation-states then, Fourth Generation Warfare now.