Early last month Attorney General Avichai Mandelblit discussed the question of whether Prime Minister Netanyahu can continue to hold office while three criminal cases are being conducted against him. Though the Supreme Court had already ruled that Netanyahu can serve as prime minister until the final verdict, Mandelblit is still toying with the idea of declaring Netanyahu unfit and thus forcing him out of office.

Given the Supreme Court’s decision it would seem that the question of Netanyahu’s “incapacity” to serve would have been put to rest. But no, the Attorney General is still determined to hang the Sword of Damocles over Netanyahu’s head. To do so he needs legal justification, which he has found in what he terms “substantive incapacity.”

This hitherto unknown legal term means that the Attorney General can declare Netanyahu’s incapacity if he thinks that the prime minister cannot faithfully fulfill his duties, mainly because of...