Any disruptions of the Gulf oil supply (primarily to Europe and China) would be temporary and would not be catastrophic. However American deaths would be tragic and could never be recovered. Also every time an American bomb is dropped or American soldiers fire their guns, more and more implacable, needless enemies are created who with their nihilistic mentality will sacrifice themselves to do harm to America. These entanglements are weakening America in many ways.
They love death as you love life and do not care how many of them die since they are all martyrs and guaranteed Paradise. More troops die in training accidents then overseas these days.