The US could lose a future war against Russia or China, a new report to Congress has suggested.

America is losing its edge while rivals innovate and blend conventional, cyber and even non-military capabilities to gain the upper hand in key regions, according to a dozen national security experts tasked by politicians with scrutinising Donald Trump’s national defence strategy.

The bipartisan group, led by former undersecretary of defence Eric Edelman and Gary Roughead, an ex-chief of naval operations, wrote: “The US military could suffer unacceptably high casualties and loss of major capital assets in its next conflict.

“It might struggle to win, or perhaps lose, a war against China or Russia. The United States is particularly at risk of being overwhelmed should its military be forced to fight on two or more fronts simultaneously. US military superiority is no longer assured and the implications for American interests and American security are severe.”

The unquestioned dominance the US enjoyed at the end of the Cold War no longer holds, the expert commission concluded following interviews with key defence officials and reviews of secret documents, and Washington faces serious challenges to its interests in Asia, Europe and the Middle East.

The experts identified Mr Trump’s tax reform bill – which greatly benefited the most wealthy – as having drained potential defence funding, alongside tax cuts by both his immediate predecessors. The White House should look to increase taxation and slash entitlements to drastically increase funding available for the military despite the short-term “pain” the move would cause, they suggested.

The US spends more than any other country on defence – budgeting $716bn in 2019, about three times the investment made by the next-biggest spender, China, in 2018. Its military is the most powerful in the world, boasting the most powerful navy with 11 nuclear-powered supercarriers; 1.3 million active-duty troops; the most advanced fighter aircraft; the second-biggest nuclear arsenal, after Russia; and decades of experience of close working between its separate branches. The US has used its armed forces to project influence around the world for more than a century, though not always successfully.

Despite all that, the commission recommended that the base defence budget be increased by between 3 and 5 per cent above inflation over the next several years. According to the authors, Barack Obama’s 2011 Budget Control Act had had “pronounced detrimental effects on the size, modernisation, and readiness of the military”. Mr Trump made building up America’s armed forces a central campaign pledge and the experts said his strategy was on the right track, but did not go far enough.

Providing For The Common Defence, their report, claimed the US was in the grip of a “full-blown national security crisis” because “the number and geographic diversity of security challenges, the technical sophistication of US rivals and adversaries, and other factors, mean that America’s military capabilities are insufficient to address the growing dangers the country faces”.

In particular it identified hybrid warfare and what is known as “grey-zone aggression – intimidation and coercion in the space between war and peace – [which] has become the tool of choice for many”. The authors included senior former Defence Department staffers, ex-diplomats, a former CIA deputy director, a senator, former senior military personnel, and think-tank experts.

They said China posed a “particularly daunting” strategic threat due to “predatory economic statecraft” and its build-up in the South China Sea, a major global shipping route, as well as rapid military reform. Beijing has created new islands in the South China Sea and equipped them with both weaponry and bases, extending its influence over waters it claims as its own – to the consternation of Washington, London and its regional neighbours.

Both US Navy and Royal Navy vessels have sailed through the South China Sea region to assert freedom of navigation rights. America’s former top admiral in the Pacific, and current ambassador to South Korea, has repeatedly warned of Beijing’s ambitions in the area and said earlier this year that the US should prepare for conflict there. America’s Pacific Command would “struggle to compete with” the People’s Liberation Army unless the threat was taken seriously, Harry Harris told Congress.

The USS Gerald R Ford, the latest American supercarrier and the first new design for such a ship in 40 years (US Navy)

Mr Trump has frequently denounced what he called Beijing’s “unfair trade practices” and launched a trade war by instituting tariffs between the two countries.

His defence plan drew praise for emphasising competition with China and Russia as the key issue shaping the US military’s future, but the experts said it did not “articulate clear approaches to succeeding in peacetime competition or wartime conflict against those rivals”. Special focus must be placed on technological advancement and interoperability, they added.

Meanwhile, Iran and North Korea were expanding their military capacity, the authors said, and jihadist groups constituted a fifth “credible challenger” on the global stage. The US must have a military able to fight two wars at once, they wrote, as opposed to Mr Trump’s plan for “what is functionally a one-war force sizing construct”.

Kathleen Hicks, one of the report’s authors and the international security director of the Centre for Strategic and International Studies think-tank, told The Washington Post: “There is a strong fear of complacency, that people have become so used to the United States achieving what it wants in the world, to include militarily, that it isn’t heeding the warning signs.”

But Dr Nicola Leveringhaus, a war studies lecturer at King’s College London, told The Independent that a US defeat by China “remains unlikely”, despite Beijing’s “advancements in conventional and asymmetric, especially cyber and AI, technology”. She said: “China cannot realistically catch up in the near to medium term with the US military in either a qualitative or quantitative sense [because] it does not have the economy or skills to do so.”

She also said: “The bigger, and more likely fear, is of escalation to a nuclear level involving China or Russia. This could happen inadvertently, from either side, through poor communication and the deployment of dual-use weapons systems that can be mistaken as escalatory in nature.”

Both the US and China would prefer to avoid a war, she said, but added: “Unfortunately, neither side has managed to set up continuous and regular “track one” [official diplomatic] meetings that cover military issues, and the militaries don’t talk to one another at a high level.

“Misunderstandings and poor communication are a big problem in bilateral relations. This problem existed under Obama too, the difference now under Trump is that the public narrative, especially from the bipartisan US side, is far more recriminatory and anti-China, and there was no “trade war” under Obama.”

World news in pictures Show all 50 1 /50 World news in pictures World news in pictures 14 September 2020 Japan's Prime Minister Shinzo Abe, Chief Cabinet Secretary Yoshihide Suga, former Defense Minister Shigeru Ishiba and former Foreign Minister Fumio Kishida celebrate after Suga was elected as new head of the ruling party at the Liberal Democratic Party's leadership election in Tokyo Reuters World news in pictures 13 September 2020 A man stands behind a burning barricade during the fifth straight day of protests against police brutality in Bogota AFP via Getty World news in pictures 12 September 2020 Police officers block and detain protesters during an opposition rally to protest the official presidential election results in Minsk, Belarus. Daily protests calling for the authoritarian president's resignation are now in their second month AP World news in pictures 11 September 2020 Members of 'Omnium Cultural' celebrate the 20th 'Festa per la llibertat' ('Fiesta for the freedom') to mark the Day of Catalonia in Barcelona. Omnion Cultural fights for the independence of Catalonia EPA World news in pictures 10 September 2020 The Moria refugee camp, two days after Greece's biggest migrant camp, was destroyed by fire. Thousands of asylum seekers on the island of Lesbos are now homeless AFP via Getty World news in pictures 9 September 2020 Pope Francis takes off his face mask as he arrives by car to hold a limited public audience at the San Damaso courtyard in The Vatican AFP via Getty World news in pictures 8 September 2020 A home is engulfed in flames during the "Creek Fire" in the Tollhouse area of California AFP via Getty World news in pictures 7 September 2020 A couple take photos along a sea wall of the waves brought by Typhoon Haishen in the eastern port city of Sokcho AFP via Getty World news in pictures 6 September 2020 Novak Djokovic and a tournament official tends to a linesperson who was struck with a ball by Djokovic during his match against Pablo Carreno Busta at the US Open USA Today Sports/Reuters World news in pictures 5 September 2020 Protesters confront police at the Shrine of Remembrance in Melbourne, Australia, during an anti-lockdown rally AFP via Getty World news in pictures 4 September 2020 A woman looks on from a rooftop as rescue workers dig through the rubble of a damaged building in Beirut. A search began for possible survivors after a scanner detected a pulse one month after the mega-blast at the adjacent port AFP via Getty World news in pictures 3 September 2020 A full moon next to the Virgen del Panecillo statue in Quito, Ecuador EPA World news in pictures 2 September 2020 A Palestinian woman reacts as Israeli forces demolish her animal shed near Hebron in the Israeli-occupied West Bank Reuters World news in pictures 1 September 2020 Students protest against presidential elections results in Minsk TUT.BY/AFP via Getty World news in pictures 31 August 2020 The pack rides during the 3rd stage of the Tour de France between Nice and Sisteron AFP via Getty World news in pictures 30 August 2020 Law enforcement officers block a street during a rally of opposition supporters protesting against presidential election results in Minsk, Belarus Reuters World news in pictures 29 August 2020 A woman holding a placard reading "Stop Censorship - Yes to the Freedom of Expression" shouts in a megaphone during a protest against the mandatory wearing of face masks in Paris. Masks, which were already compulsory on public transport, in enclosed public spaces, and outdoors in Paris in certain high-congestion areas around tourist sites, were made mandatory outdoors citywide on August 28 to fight the rising coronavirus infections AFP via Getty World news in pictures 28 August 2020 Japanese Prime Minister Shinzo Abe bows to the national flag at the start of a press conference at the prime minister official residence in Tokyo. Abe announced he will resign over health problems, in a bombshell development that kicks off a leadership contest in the world's third-largest economy AFP via Getty World news in pictures 27 August 2020 Residents take cover behind a tree trunk from rubber bullets fired by South African Police Service (SAPS) in Eldorado Park, near Johannesburg, during a protest by community members after a 16-year old boy was reported dead AFP via Getty World news in pictures 26 August 2020 People scatter rose petals on a statue of Mother Teresa marking her 110th birth anniversary in Ahmedabad AFP via Getty World news in pictures 25 August 2020 An aerial view shows beach-goers standing on salt formations in the Dead Sea near Ein Bokeq, Israel Reuters World news in pictures 24 August 2020 Health workers use a fingertip pulse oximeter and check the body temperature of a fisherwoman inside the Dharavi slum during a door-to-door Covid-19 coronavirus screening in Mumbai AFP via Getty World news in pictures 23 August 2020 People carry an idol of the Hindu god Ganesh, the deity of prosperity, to immerse it off the coast of the Arabian sea during the Ganesh Chaturthi festival in Mumbai, India Reuters World news in pictures 22 August 2020 Firefighters watch as flames from the LNU Lightning Complex fires approach a home in Napa County, California AP World news in pictures 21 August 2020 Members of the Israeli security forces arrest a Palestinian demonstrator during a rally to protest against Israel's plan to annex parts of the occupied West Bank AFP via Getty World news in pictures 20 August 2020 A man pushes his bicycle through a deserted road after prohibitory orders were imposed by district officials for a week to contain the spread of the Covid-19 in Kathmandu AFP via Getty World news in pictures 19 August 2020 A car burns while parked at a residence in Vacaville, California. Dozens of fires are burning out of control throughout Northern California as fire resources are spread thin AFP via Getty World news in pictures 18 August 2020 Students use their mobile phones as flashlights at an anti-government rally at Mahidol University in Nakhon Pathom. Thailand has seen near-daily protests in recent weeks by students demanding the resignation of Prime Minister Prayut Chan-O-Cha AFP via Getty World news in pictures 17 August 2020 Members of the Kayapo tribe block the BR163 highway during a protest outside Novo Progresso in Para state, Brazil. Indigenous protesters blocked a major transamazonian highway to protest against the lack of governmental support during the COVID-19 novel coronavirus pandemic and illegal deforestation in and around their territories AFP via Getty World news in pictures 16 August 2020 Lightning forks over the San Francisco-Oakland Bay Bridge as a storm passes over Oakland AP World news in pictures 15 August 2020 Belarus opposition supporters gather near the Pushkinskaya metro station where Alexander Taraikovsky, a 34-year-old protester died on August 10, during their protest rally in central Minsk AFP via Getty World news in pictures 14 August 2020 AlphaTauri's driver Daniil Kvyat takes part in the second practice session at the Circuit de Catalunya in Montmelo near Barcelona ahead of the Spanish F1 Grand Prix AFP via Getty World news in pictures 13 August 2020 Soldiers of the Brazilian Armed Forces during a disinfection of the Christ The Redeemer statue at the Corcovado mountain prior to the opening of the touristic attraction in Rio AFP via Getty World news in pictures 12 August 2020 Young elephant bulls tussle playfully on World Elephant Day at the Amboseli National Park in Kenya AFP via Getty World news in pictures 11 August 2020 French Prime Minister Jean Castex is helped by a member of staff to put a protective suit on prior to his visit at the CHU hospital in Montpellier AFP via Getty World news in pictures 10 August 2020 Locals harvest their potatoes as Mount Sinabung spews volcanic ash in Karo, North Sumatra province, Indonesia Antara Foto/Reuters World news in pictures 9 August 2020 Doves fly over the Peace Statue at Nagasaki Peace Park during the memorial ceremony held for the 75th anniversary of the atomic bombing EPA World news in pictures 8 August 2020 Anti-government protesters try to remove concrete wall that installed by security forces to prevent protesters reaching the Parliament square, during a protest against the political elites and the government after this week's deadly explosion in Beirut AP World news in pictures 7 August 2020 A protester throws a stone towards Israeli forces in the village of Turmus Aya, north of Ramallah in the occupied West Bank, following a march by Palestinians against the building of Israeli settlements AFP via Getty World news in pictures 6 August 2020 A woman yells as soldiers block a road for French President Emmanuel Macron's visit the Gemmayzeh neighborhood. The area in Beirut suffered extensive damage from the explosion at the seaport AP World news in pictures 5 August 2020 Damage at the site of Tuesday's blast in Beirut's port area, Lebanon Reuters World news in pictures 4 August 2020 A large explosion in the Lebanese capital Beirut. The blast, which rattled entire buildings and broke glass, was felt in several parts of the city AFP via Getty World news in pictures 3 August 2020 A general view shows the new road bridge in Genoa, Italy ahead of its official inauguration, after it was rebuilt following its collapse on August 14, 2018 which killed 43 people Reuters World news in pictures 2 August 2020 Empty stall spaces are seen hours before a citywide curfew is introduced in Melbourne, Australia EPA World news in pictures 1 August 2020 People take part in a demonstration by the initiative "Querdenken-711" with the slogan "the end of the pandemic - the day of freedom" to protest against the current measurements to curb the spread of COVID-19 in Berlin, Germany AFP via Getty World news in pictures 31 July 2020 Pilgrims circumambulating around the Kaaba, the holiest shrine in the Grand mosque in Mecca. Muslim pilgrims converged today on Saudi Arabia's Mount Arafat for the climax of this year's hajj, the smallest in modern times and a sharp contrast to the massive crowds of previous years Saudi Ministry of Media/AFP World news in pictures 30 July 2020 The Mars 2020 Perseverance mission lifts off at the Kennedy Space Centre in Florida. The mission is part of the USA's largest moon to Mars exploration. Nasa will attempt to establish a sustained human presence on and around the moon by 2028 through their Artemis programme EPA World news in pictures 29 July 2020 A woman refreshes herself in a outdoor pool in summer temperatures in Ehingen, Germany dpa via AP World news in pictures 28 July 2020 Malaysia's former prime minister Najib Razak speaks to the media after he was found guilty in his corruption trial in Kuala Lumpur AFP via Getty World news in pictures 27 July 2020 North Korean leader Kim Jong Un poses for a photograph after conferring commemorative pistols to leading commanding officers of the armed forces on the 67th anniversary of the "Day of Victory in the Great Fatherland Liberation War". Which marks the signing of the Korean War armistice KCNA via Reuters

Addressing international concern over China’s increased activity in the South China Sea, Dr Leveringhaus told The Independent Beijing was now reaping the benefits of a “decades-long military modernisation underway especially since Jiang Zemin and Hu Jintao, of which certain new weapons systems are now coming online under Xi Jinping”.

She added: “Given that China was such a weak military power in the 1970s and 1980s, the results of its military modernisation [as] evidenced in its navy especially, but also in the next decade in its air force too, this presents a fundamentally stronger military China – the strongest People's Republic in military terms since its establishment in 1949.

“This is uncomfortable for regional powers that are already concerned by China’s broader re-emergence and economic power, and upsetting to a US that has been militarily dominant and unrivalled in Asia since the mid to late 1940s.”

Defence officials said on Thursday that the US military would withdraw hundreds of troops from counter-terrorism missions in Africa to bolster the Pentagon’s focus on opposing China and Russia as part of the plan laid out in Mr Trump’s national defence strategy. Russia, however, recently suffered a blow to its force projection capacity when a huge dry dock holding its sole aircraft carrier, the ageing Admiral Kuznetsov, sank, putting back the Soviet-era vessel’s refit by months or even years.

Vladimir Putin has been forthright about his desire to strengthen Russia’s military and has boasted particularly of its missile capacity and innovations.

China, which bought Kuznetsov’s sister hull for use as a training ship and converted it into the Liaoning, has since launched its own home-grown aircraft carrier called the Type 001A.

Also on Thursday, Mike Pence told leaders of southeast Asian countries that “empire and aggression have no place in the Indo-Pacific”. Speaking in Singapore but without mentioning China directly, he added: “Like you, we seek an Indo-Pacific in which all nations, large and small, can prosper and thrive, secure in our sovereignty, confident in our values, and growing stronger together”.

Support free-thinking journalism and attend Independent events

On Friday, North Korea announced its leader, Kim Jong-un, had observed a successful test of a new “tactical weapon” which the official propaganda agency, KCNA, said could protect the country like a “steel wall”. And just days ago commercial satellite images revealed more than a dozen undeclared North Korean missile bases.

Mr Trump and Mr Kim signed an agreement to work towards “denuclearisation” on the peninsula during their unprecedented meeting earlier this year, but little headway has been made since.

The US president, while saying he will build up his own military forces, has also berated his Nato allies for failing to do the same. Europe should no longer take American military support for granted, he has said, urging other Nato countries to meet the defence spending target of 2 per cent of GDP in often undiplomatic language.

Yet the defence strategy, published by his government, acknowledged that “mutually beneficial alliances and partnerships are crucial to our strategy, providing a durable, asymmetric strategic advantage that no competitor or rival can match”.