The US Air Force has released a new image and details of its next-generation B-21 Raider stealth bomber, which defence experts say is apparently part of efforts to counter threats posed by China and Russia ’s military modernisations. While the artist rendering does not give away much of the design, the air force said in a statement on Tuesday that it would be part of America’s “nuclear triad” of options to strike by air, ground or submarine. “The built-in feature of open systems architecture on the B-21 makes the bomber effective as the threat environment evolves,” Randall Walden, director of the Air Force Rapid Capabilities Office, said in the statement. “This aircraft design approach sets the nation on the right path to ensuring America’s enduring air power capability.” The bomber’s “open systems architecture” will allow it to engage with other advanced aircraft platforms and weapon systems that are designed for modern warfare, according to military experts. Ben Ho, an air power analyst at the S. Rajaratnam School of International Studies in Singapore, said the evolving “threat environment” appeared to be about China and Russia. “[Walden] was arguably referring to the increasing threat posed by near-peer competitors China and Russia as they not only modernise their nuclear arsenals, but also their air defences,” Ho said. “It is also conceivable that the B-21 is meant as a like-for-like counter to China’s H-20 strategic stealth bomber that may fly next year, and that has arguably accelerated the B-21 programme.” China announced it was developing the long-range H-20 bomber in 2016 but has yet to release any images or give a date for it to go into service. It is expected to be equipped with nuclear and conventional missiles and be part of the People’s Liberation Army “nuclear triad”. Russia, meanwhile, is developing its own next-generation strategic bomber, the PAK-DA, which is expected to go into service in 2027. It also claims its newest Nebo-M surveillance radar system can detect US stealth aircraft. Zhou Chenming, a researcher with the Yuan Wang military science and technology institute in Beijing, noted that the US Air Force had put the average cost of each B-21 at US$639 million, with at least 100 to be built. He expected the H-20 would be produced for less. “These aircraft [B-21s] will be used over the next 50 years,” Zhou said. “The procurement cost of the B-21s will be much cheaper than for the larger bomber B-2 Spirit, which costs US$2 billion and is expensive to operate.” The US Air Force plans to replace its fleet of B-2s and B-1 Lancers with the B-21 bombers, which are expected to go into service in the mid-2020s and are being made by Northrop Grumman. Another long-range strategic bomber, the B-52 Stratofortress, is being upgraded so that it can continue to fly into the 2050s. As tensions have been rising over the South China Sea in recent years, the US has been sending its B-2 and B-52 bombers over disputed islands claimed by China, Vietnam, the Philippines and others in the region. Zhou expected the B-21s to be used for such patrols in the future. “Since the procurement and operating costs of the B-21 bombers will be much lower than for the B-2s and B-52s, it is foreseeable that the new bomber will be sent over the region more frequently and more extensively than the two older aircraft once it joins the US Air Force,” he said.