Good point from a reader (though “cave” might be strong):

Jonah, There’s no need to cave in to the whiners. This looks to be a brutal murder or manslaughter, but not terrorism. It happened in the heat of the moment, so there is no reason to assume that the Marines were trying to terrorize anyone, to intimidate them or strike them with terror. From the Oxford English Dictionary Terrorism: A policy intended to strike with terror those against whom it is adopted; the employment of methods of intimidation; the fact of terrorizing or condition of being terrorized