You'd think that, strategically, a decapitation strike is the worst thing that could happen for a nation. However, that would be incorrect: the worst thing that could happen is this, a vain and incompetent buffoon installed in the top leadership position. With no leader you're just not making decisions, but the organization can continue operating under autonomous cells. With a hyperactive incompetent leader you're speedrunning every conceivable bad decision and everyone just has to look on in horror.