Technically, it’s probably not quite true that none pursueth. Israel is probably watching. But Israel apparently didn’t attempt to interdict the first shipment of S-300 components from Russia to Iran, and that looks to be for a logical reason.
That said, the delivery, which came across the Caspian Sea, was encased in heavy security, as if Russia and Iran were really worried about something:
Following a protracted process with numerous twists and turns, Russia finally appears to have begun delivering at least some elements of the S-300 long-range air-defense system to Iran. On April 11, exactly one year after President Vladimir Putin lifted his ban on such deliveries, a convoy of ships offloaded large equipment at the Caspian port of Anzali, under a heavy guard that included extensive deployment of Iranian air-defense reinforcements. The equipment was then transported by road to Tehran.
This shipment was the least likely of any to be attacked, because it appears to have featured only the radars associated with the S-300 systems Iran is buying.
[P]hotos have shown large flatbed trucks in Iran transporting what appear to be partially camouflaged components of the ST68U/UM Tin Shield and 64N6E Big Bird search-and-acquisition radars associated with the older PMU-1 version, in addition to other unidentified equipment. So far, none of the available imagery shows the fire-control radars or missile transporter erector launchers (TELs) associated with a complete S-300 firing unit.
Having the radars doesn’t give Iran an increased capability to actually shoot down aircraft. For that, the missiles, launchers, and control vehicles will be required.
We can assume at this point that the U.S. will make no attempt to interfere with a complete delivery of the S-300 systems, which Russia and Iran say will be before the end of 2016. Although Israel still may intervene in some way, these first components are not worth shooting the silver bullet over, because they don’t significantly increase Iran’s combat capability. That’s the simplest logical reason for holding fire, for now.
Farzin Nadimi, The Washington Institute’s author, points out that the radars seen heading for Tehran indicate delivery of the S-300PMU-1 system, rather than the PMU-2, which observers have long thought Iran was buying. The PMU-1 is an older, less formidable system – although that shouldn’t mislead us. It will still represent a significant upgrade over Iran’s current air defenses. Used to provide saturated coverage for areas of the country, it will greatly increase the effort an attacking air force has to put into suppressing the air defenses, in order to get its attackers to their targets.
So the countdown clock has begun to Israel’s decision point on what to do about the S-300. The circumstances will be as difficult as they could be, with the Western powers invested in the JCPOA, and Obama desperate to keep Iran from ignoring it entirely. (Since Iran hasn’t signed anything, it would be inaccurate to refer to any possibility of the Iranians “pulling out” of it. There’s no “pull out” about it.)
But Israel would be fully justified in declining to assume that the JCPOA will keep Iran from developing nuclear weapons for the next 10 years.
And that said, time and Iranian progress have continued to change the nature of the interdiction problem against Iran’s nuclear weapons program. The critical nodes haven’t been the big installations at Natanz or Esfahan for some time now, or even the hardened facility at Fordo. What Iran has yet to master – mating a working warhead to a missile – will probably take place at some combination of Parchin, one or more additional “industrial” facilities, a warhead testing site somewhere else – and very possibly North Korea.
Preventing anything in North Korea is not an option for Israel, but interdicting shipments between the two countries is feasible (if by no means simple, or guaranteed).
The overall interdiction problem posed by the Iranian nuclear weapons program, as a proposition for military forces, is less of a matter of massed air attack than it would have been 10 years ago. The objectives of an operation, especially one mounted in 2016, before the U.S. has elected our next president, would be different from what they would have been in 2006. If Israel has to conduct an attack of some kind this year, to forestall an imminent development, it will very much matter to the scope of the operation if the decision has to be before or after November 2016 – and if after, it will matter who has been elected.
My best estimate is that the Israelis will be able to avoid having to mount a massed, frontal air attack this year. That doesn’t mean they won’t have to do anything.