Patrick Wintour writes: The recent claims by the Syrian opposition and the United Nations that Russia is using bunker-buster bombs in Aleppo would, if proven, confirm that a new, more destructive phase in the Russian assault on rebel forces is under way, and that the diplomatic track is effectively closed.

The bombs – capable of destroying underground shelters and command centres – would also suggest Russia is determined to bring the months-long siege of Aleppo to a speedy end, and that they have high-grade intelligence of the whereabouts of Syrian opposition positions.

Justin Bronk, research fellow at the defence thinktank RUSI, explained that bunker-busters are a very specific kind of destructive precision weaponry. “They show up as very different-shaped craters. They go very deep and explode deep underground so they tend to leave deeper but less wide craters than other bombs.”

He added it was very unlikely Russia would use such specific bombs at random or simply to blitz a city since they are very expensive and require specific targeting intelligence to be worth using. If they hit an underground shelter the number of deaths would be huge, but it would be much lower than other generalised heavy bombs if no specific target had been located. [Continue reading…]