Today marks four months since the attack on our consulate in Benghazi, which killed our ambassador and three other Americans. Justice still has not been done—and it looks increasingly unlikely that it will ever be done.

Just a couple of days ago a Tunisian court freed Ali Harza, a Tunisian man who was one of the few to be charged in connection with the assault. This is what comes from giving the FBI the lead in the response to this assault on American territory. The criminal investigation appears to be going nowhere fast, which is hardly surprising given how hard it is to gather evidence and bring indictments under such chaotic conditions. The only mystery is why this isn’t being treated as what it is—an act of war on the United States that deserves a military response.

The Obama administration does not hesitate to use extra-judicial means to kill our enemies in Pakistan, Yemen, or Somalia, but in Libya it appears to be hamstrung by legalistic niceties. There are, to be sure, legitimate concerns about undermining the sovereignty of a fledgling pro-American regime. But while unilateral American action could prove embarrassing for Libyan officials, doing nothing is the worst course of all. It sends a signal—similar to the non-response to the USS Cole bombing by the Clinton and Bush administrations—that a symbol of America can be attacked and Americans killed with impunity. That is a very dangerous message to send in a very rough region of the world.