There has been a good deal of informed speculation in the press regarding the Israeli Air Force’s Sept. 6 raid on a suspected nuclear development site in Syria. (See, for instance, Bret Stephens’s excellent column in the Wall Street Journal.) Two aspects of the raid haven’t received enough attention, however.

First, the fact that the Israeli Air Force was able to catch the Syrians by surprise. There is no indication that any Israeli aircraft were shot down or even damaged. This is pretty significant: Syria has been making an effort to upgrade its air defenses in recent years by buying Russian-made surface-to-air missiles. Yet Israeli F-15 and F-16 fighter-bombers were still able to strike deep into Syria unscathed.

Second, Syria has not (so far at least) mounted any kind of retaliation that we know of. Perhaps some counter-blow—possibly in the form of a terrorist attack against Israelis or even non-Israeli Jews—is coming. But so far the Syrian response can only be described as very muted. Perhaps the Syrians realize that, if they escalate the conflict, Israel can do far worse to Syria than Syria can do to Israel.

What do these two facts combined mean? They suggest that both Syria and its Iranian patrons (who have also been upgrading their air defenses with Russian help) remain very vulnerable to air attack by a sophisticated state like Israel or the United States. That increases the pressure on these “axis of evil” members to rethink their continuing efforts to facilitate attacks on Western forces in Iraq and to develop nuclear-weapons. They must know that whatever the Israeli Air Force can do, the U.S. Air Force can do on much bigger scale. If anything will lead them to negotiate seriously, that is it.

Even so, I can’t say I have much hope they will mend their ways until they see that the U.S. has not only the capability to hurt them but also the willingness to do so. As the Journal’s editorial board argues today, Tehran has been told it will pay a price for killing Americans, but it never has.”