The intolerability of nuclear weapon usage is not a simple binary. We didn't have the same kind of security agreements with Ukraine that we do with NATO countri

The intolerability of nuclear weapon usage is not a simple binary. We didn't have the same kind of security agreements with Ukraine that we do with NATO countries, hence we are not at war with Russia. Had Russia invaded a NATO country, we still would not have launched first, but rather used conventional weapons, given the fallout (literal and metaphorical), but actually using them to prevent greater numbers of casualties from protracted war is not fully off the table, so to speak.