Chinese military analysts have closely followed Saturday鈥檚 US strikes on Iranian facilities, and especially the bombs used 鈥 the GBU-57, a powerful 鈥渂unker buster鈥 designed to penetrate deeply buried targets.
While praising the success of the B-2鈥檚 long-range delivery and the bunker buster鈥檚 performance, they also pointed out the limitations in its effectiveness, especially against sites like Fordow that are deep underground.
Mainland China is believed to have the world鈥檚 most extensive underground bunker systems and its own bunker-busting weapons, as well as ambitions to target facilities, including those deep within the mountains of Taiwan.
What did the US bomber strike entail and how is the action viewed by Chinese military analysts? And what is China鈥檚 approach to the development of its own bunker-busting arsenal?
Combat debut
A total of 14 GBU-57 Massive Ordnance Penetrators (MOPs) were dropped by seven B-2 stealth bombers in the early hours of Sunday local time, striking Iran鈥檚 heavily fortified Fordow nuclear site as well as facilities at Natanz.
The operation marked the combat debut for the world鈥檚 most powerful non-nuclear bunker buster 鈥 a type of munition specifically designed to penetrate hardened or deeply buried targets beyond the reach of conventional bombs.
Bunker busters such as the GBU-57 differ from typical bombs because they burrow into the ground before detonation, exponentially increasing their destructive potential.
Weighing around 30,000 pounds (13,600kg), the GBU-57 is the largest non-nuclear bomb in the US arsenal. It is believed to be capable of penetrating up to 60 metres (197 feet) of reinforced concrete or rock, depending on the material it encounters.
Due to its size, it can only be carried by B-2 bombers, with each aircraft able to carry up to two MOPs at a time. The US military is estimated to have around 20 of these bombs, according to American media reports.
While Israel does not have the GBU-57, the Centre for Strategic and International Studies (CSIS) says it is equipped with the less powerful GBU-28 and the BLU-109. Neither has the penetration capability to reach the Fordow facility around 80 metres (262 feet) underground.
Trump declared that the targets were 鈥渢otally obliterated鈥 in the strike. However, Pentagon officials adopted a more cautious tone, calling the damage to the sites 鈥渟evere鈥, while adding that a final damage assessment would take time.
Chinese analysts react
Military expert Du Wenlong described the B-2鈥檚 37-hour mission 鈥 the second-longest in the aircraft鈥檚 history 鈥 as a success, based on its range, accompanying aircraft and the use of decoys. However, he emphasised that the strike鈥檚 true impact remained uncertain.
鈥淎lthough the strike successfully hit its targets, the extent of internal damage is unclear,鈥 Du said, noting that there was a gap of about 30 metres (98 feet) between the GBU-57鈥檚 penetration depth and the location of Fordow鈥檚 core.
鈥淭he strike may have damaged the mountain structure, but whether it hit the actual facility is undetermined,鈥 he said.
Du鈥檚 assessment was echoed by analyst Song Zhongping, who drew attention to satellite imagery showing six craters near the facilities. It appeared that every two bombs were aimed at each specific target 鈥 possibly in an attempt to reinforce penetration, he said.
鈥淚f the goal was complete destruction of facilities like Fordow or Natanz, the mission likely fell short. Iran had likely relocated critical nuclear materials, and while some infrastructure may have been damaged, total elimination is improbable,鈥 Song added.
China鈥檚 bunker busters
China has developed its own suite of bunker-penetrating weapons, with an emphasis on land-based ballistic missile delivery systems.
The DF-15C, unveiled in 2013, is a variant of China鈥檚 short-range ballistic missile designed specifically for precision strikes on hardened underground targets.
According to nationalist tabloid Global Times, the DF-15C features a long cylindrical penetrator warhead 鈥 around 2 to 2.5 metres (6ft 7in to 8ft) long 鈥 designed to breach reinforced concrete and underground bunkers.
With a range of around 700km (435 miles), the missile gives the People鈥檚 Liberation Army a significant regional strike capability, with targets in Okinawa, northern Vietnam, New Delhi and Taiwan reportedly in reach.
The DF-15C is understood to be capable of targeting underground command centres and hardened shelters, including the Taiwanese military facility in Yushan, the island鈥檚 highest peak, the article said.
In 2014, the party mouthpiece People鈥檚 Daily reported that China鈥檚 state-owned defence giant Norinco showcased its GB1000 series of 1,000kg (2,200 pounds) guided bombs at the country鈥檚 annual Zhuhai air show.
According to the article, these bombs are compatible with various penetrating and fragmentation warheads and are designed to destroy hardened ground targets such as reinforced aircraft hangars, underground bunkers, and transport hubs.
It is unknown how far underground the Chinese bunker busters can travel.
Song noted that China had taken a 鈥渄istinct approach鈥 to the technology compared to the United States by opting to emphasise ballistic missile-based delivery for bunker-busting missions.
鈥淚 believe different countries pursue different strategies. China鈥檚 advantage lies in ballistic missiles, and we should continue to refine and master that capability,鈥 he said.
鈥淎s for the US strike this time, while it was expected, it was far from perfect. In fact, it shows that airdropped munitions from manned bombers may not be the most effective solution in future warfare.鈥