As Jonathan noted earlier, the Obama administration’s behavior to date has given Egypt every reason to think it can let a mob attack the U.S. embassy in Cairo with impunity. But there’s a very specific precedent he failed to mention: Just two weeks ago, a Cairo court sentenced 76 people indicted over last September’s mob attack on Israel’s embassy in Cairo. The net result is that not a single person is going to jail over that attack, sending the clearest possible message that mobs can attack foreign embassies in Cairo with impunity. Yet no world leader has lodged even a pro forma protest over this decision.

A brief recap: On September 9, 2011, thousands of Egyptians stormed the Israeli embassy, broke through the security wall and proceeded to loot it. No Israeli diplomats were present at the time, but six Israeli security guards were, and Israel was afraid they would be lynched: They had barricaded themselves in an interior room, but the mob was trying to break down the door. And not only did Egyptian police do nothing to stop the assault, but government officials in Cairo refused even to take calls from their frantic Israeli counterparts. Only after Washington intervened did the Egyptians finally send troops to rescue the Israelis.

The attack was denounced by leaders and diplomats worldwide, and ultimately, 76 people were put on trial for it, as well as for having stoned the nearby Saudi embassy-or, at least, so say various foreign media reports. Two Egyptian media sources, MENA and Al-Ahram, actually reported the indictments as being for attacking the Saudi embassy only, meaning those who attacked Israel’s embassy enjoyed complete immunity.

Either way, the charges were weighty, including “an assault against diplomatic missions” and “sabotage.” But the sentences handed down on August 26 were a joke: All the defendants received suspended sentences except for one who was tried in absentia. He was sentenced to five years, but according to Al-Ahram, less for the embassy attack than for “inciting violence against police” by authoring a book about police brutality and torture. And in any case, since he’s abroad, he won’t be serving any time, either.

The message couldn’t be clearer: The Egyptian legal system doesn’t view attacking embassies as a serious crime. Yet no world leader or diplomat thought this message worth protesting. Indeed, just a week after that verdict, the Obama administration announced that it was about to approve a sweeping debt forgiveness deal for Egypt, and would also back Egypt’s request for a $4.8 billion International Monetary Fund loan. Is it any wonder if official Egypt concluded that Washington doesn’t care all that much about embassy attacks?

The man on the street got the message as well: Attacking embassies is a risk-free endeavor. And today, a crowd of them applied this lesson by attacking another.