“Enough of them” is a much higher percentage than of other populations. While killing them you need to deny them resources. Were the West serious about beating back the current Islamic Wave it would cut off all commerce with Moslem countries and would colonize the oilfields and pump them purely for their own profit.
“...colonize the oilfields and pump them purely for their own profit.”
And when the cries about “blood for oil” echo across the land, they would simply smile and say, “Yes. And you’re welcome.”