In the face of massive Palestinian protests, Israel this week agreed to remove the metal detectors that it installed at the Temple Mount in Jerusalem after the terrorist murder there of two Israeli policemen. The episode, Martin Kramer writes,

has raised the question of just what constitutes legitimate security measures at Islamic holy shrines and iconic mosques. We live in a time when the primary threat to the security of these sites arises from Muslims themselves—notably, extremists bent on using them as launching pads for violent acts designed to destabilize and terrorize. Across the Muslim world, governments are acutely aware of the vulnerabilities of these sites, and have taken measures to secure them. In particular, they have resorted to a commonplace technology: metal detectors.

Here I provide some prime examples from Egypt, Iran, Iraq, Saudi Arabia, Syria, and the United Arab Emirates. . . . Off we go on a quick tour—with photographs—of Islam’s bucket list of top sites. Please place your keys and camera in the basket.

There is little doubt that if Hizballah had participated more intensively in Saturday’s attack, Israeli air defenses would have been pushed past their limits, and far more damage would have been done. Daniel Byman and Kenneth Pollack, trying to look at things from Tehran’s perspective, see this as an important sign of caution—but caution that shouldn’t be exaggerated:

Iran is well aware of the extent and capability of Israel’s air defenses. The scale of the strike was almost certainly designed to enable at least some of the attacking munitions to penetrate those defenses and cause some degree of damage. Their inability to do so was doubtless a disappointment to Tehran, but the Iranians can probably still console themselves that the attack was frightening for the Israeli people and alarming to their government. Iran probably hopes that it was unpleasant enough to give Israeli leaders pause the next time they consider an operation like the embassy strike.

Hizballah is Iran’s ace in the hole. With more than 150,000 rockets and missiles, the Lebanese militant group could overwhelm Israeli air defenses. . . . All of this reinforces the strategic assessment that Iran is not looking to escalate with Israel and is, in fact, working very hard to avoid escalation. . . . Still, Iran has crossed a Rubicon, although it may not recognize it. Iran had never struck Israel directly from its own territory before Saturday.

Byman and Pollack see here an important lesson for America:

What Saturday’s fireworks hopefully also illustrated is the danger of U.S. disengagement from the Middle East. . . . The latest round of violence shows why it is important for the United States to take the lead on pushing back on Iran and its proxies and bolstering U.S. allies.