We will do what we have to do
How far we go will depend to some extent on how successful they are but if they keep coming there is no limit to what we will eventually do to stop them and protect our way of life.
In the long run there will be no moral dilemma. We will exterminate our enemies and any friends of our enemies or they will exterminate us. I just don't see us accepting an endless future of attacks followed by measured retaliation and endless negotiation.
I hope I am wrong. I hope that we find a way to resolve it peacefully. Maybe some great leader(s) will emerge and deliver us. I don't wish this future on my children and grandchildren but I just don't see any end to it until one side or the other is utterly defeated.