Massive Ordnance Penetrator. (Gizmodo)

As I wrote earlier, the United States and Israel embarked on a groundbreaking (figuratively) arms deal that included the sale of equipment that the United States has never before sold to another ally.

The new weapons sale package includes aircraft for midair refueling and missiles that can cripple an adversary’s air defense system. Both would be critical for Israel if it were to decide on a unilateral attack on Iran.

The V-22 Osprey, which vertically lifts off, is among the sweet things Israel may now boast in its arsenal. Iran should be nervous and Israel should be happy, nu? Apparently not. According to some sources, the deal was (quite literally) not groundbreaking enough.

But what the Israelis wanted most was a weapons system that is missing from the package: a giant bunker-busting bomb designed to penetrate earth and reinforced concrete to destroy deeply buried sites. According to both American and Israeli analysts, it is the only weapon that would have a chance of destroying the Iranian nuclear fuel enrichment center at Fordow, which is buried more than 200 feet under a mountain outside the holy city of Qum.

The weapon, called a Massive Ordnance Penetrator, weighs about 30,000 pounds — so much that Israel does not have any aircraft capable of carrying it. To do so, they would need a B-2 bomber, the stealth aircraft that the United States flew nonstop recently from Missouri to the Korean Peninsula to underscore to North Korea that it could reach their nuclear sites.

If I am understanding this correctly (which I am sure I will be challenged on), this is the incremental, happy-medium step by the United States. The diplomatic track (consisting of negotiations and sanctions) in the efforts to convince Iran to stop its nuclear program isn’t working so the arms deal is a message to them. The magnitude of the deal also sprinkles some cornstarch on the Israelis, who are increasingly watching the diplomatic approach fail and are worried Iran is just stringing everyone along.

By not giving Israel the keys to the American defense establishment’s car (which is less a car than a 15-ton bunker buster and the B-2 bomber needed to fly it), it signals there is still more time for Iran to fall in line, but shows the Israelis that President Obama and Defense Secretary Hagel aren’t sleeping on this issue.

Earlier: Massive Arms Deal Between Israel and U.S.
No Bunker-Buster Bomb in Israel’s U.S. Arms Deal [NYT]