Actually, Morris is right. Since Islam isn't going to go away, it is a reality that must be dealt with.
Dealing with it means that one must either fight it, which means having to do cruel and tragic things (since that is the definition of fighting); or one must surrender, which in this case would mean forgoing Zionism.
Your third alternative would involve either the disappearance of Islam or its radical change. A realistic leader won't count on either happening.
A liberal/socialist friend of mine rejects the very idea of war, since war "should" never be necessary. Well, sometimes it IS. We can have intense arguments about whether a given war or use of force is necessary, but anybody who rejects the principle just cannot be taken seriously.