Efforts by the US military to equip the batwinged B-2 "Spirit" Stealth bomber with a huge penetrator weapon - suitable for use against underground Iranian nuclear facilities - have been delayed.
The Massive Ordnance Penetrator (MOP) is a huge, 14-tonne steel pencil containing a relatively small 2.5-tonne explosive charge. Dropped from high altitude, it strikes at supersonic speed with terrific force, punching through many metres of concrete or earth protection before exploding.
Very similar weapons - for instance the British "Tallboy" and "Grand Slam" penetrators - designed by legendary bouncing-bomb boffin Barnes Wallis of Dambusters fame, and termed "earthquake bombs" - were used against hardened Nazi targets in World War II. An even bigger design, the colossal 20-tonne American T12, arrived too late to see action. The only significant enhancement boasted by the 14-tonne MOP over the 1940s models is precision guidance, which should mean that far fewer weapons and bombers will be needed to eliminate a target.
In the event of America deciding to take military action against Iran's nuclear programme, MOPs dropped from B-2s would seem like one of the least-worst options. The high-flying stealthy bombers would probably be able to penetrate Iranian air defences without a major battle, and the MOPs would be able to wreck even deeply-buried targets like the uranium-enrichment centrifuge bunkers of Natanz.
The effort to develop the MOP and get it deployed aboard B-2s has been underway for some years now. The US government assigned extra funds to speed things up earlier this year, but nonetheless Reuters is now reporting that the delivery date has slipped 6 months to December 2010.
"Funding delays and enhancements to the planned test schedule have pushed the capability availability date to December 2010," Tara Rigler, a Pentagon spokeswoman, told the newswire.
The MOP has been used in successful test drops already, but only from older B-52 Stratofortresses. A raid on Iran by B-52s would probably involve more fighting and casualties than one by Spirits, and Pentagon spokesmen have confirmed that the Stratofortress will not be the operational platform for the weapon.
Some analysts have suggested that less-powerful air forces like those of Israel could mount an effective raid on Iran's nuclear complex. Such an operation would involve large numbers of aircraft, a tough battle with Iran's Russian-supplied defences, serious risks of failure and certainty of major diplomatic protests - not just from Iran, but also from countries overflown by the raiders.