What is an acceptable casualty risk? That would depend on the reason for and the seriousness of the conflict (war) we decide to engage in. It was vastly different in feudal times, where such matters were not the concern of ordinary citizens; the decision rested on the whim of the feudal warlord or the king.
But what is the acceptable risk if neither war nor conflict were involved, and only involved the allowance of a certain democraphic to enter within our borders? How many deaths from violence or some act of terror is acceptable? 1 citizen death per 1,000 refugees? 1 per 10,000? 1 per 100, 000 maybe? If we let in 1,000 that our State Dept could not properly vette, and 10 women and children are slaughtered, is that an acceptable risk?
Since I personally cannot move beyond “zero” comfortably, I challenge any politician to declare a rational quantity. I double-dare any Democrat politician produce a number he or she would be perfectly comfortable with. Democrats make policy decisions exclusively on emotional motivation, rarely ever based on logical reasoning.