This year, the United States has ramped up its military activities in the South China Sea, sparking debate over why, particularly when most actors have scaled down military activities because of the pandemic. Will this – and the increasing risk of a clash – be the new normal? While the number and frequency of traditional US intelligence, surveillance and reconnaissance probes is roughly the same – hundreds each year along China’s coasts – other military activities have increased. In the first quarter of the year, the US air force has flown about three times the number of sorties over the South China Sea as in any quarter of 2019. The US navy has conducted four freedom of navigation operations in the South China Sea in the same period, including two on successive days , compared with just eight for all of 2019. In April, guided-missile cruiser USS Bunker Hill, guided-missile destroyer USS Barry and amphibious assault ship USS America “exercised” with an Australian frigate near the site of an ongoing dispute between China, Vietnam and Malaysia over exploration rights. But in case China did not get the message, the littoral combat ship USS Montgomery and support vessel USNS Cesar Chavez subsequently operated in the same area, followed by the littoral combat ship USS Gabrielle Giffords. This increased activity is probably due to a combination of factors. One theory is that the US is fed up with China across the board and the enhanced activity in such a strategic and contested sea is a signal of the fundamental deterioration in relations. Shi Yinhong, an adviser to China’s State Council, believes the US and China “are actually in the era of a new Cold War” and that their relationship has substantially changed from even a few months ago. In other words, the ratcheting up of existing tensions in the South China Sea is only part of an overall deteriorating relationship involving trade, cyber theft, Taiwan, the “international order” and the competition for hegemony in Asia. Has pandemic shifted balance of military force in the Indo-Pacific? Others argue that the enhanced US show of force is specific to the South China Sea and a response to China’s ignoring of earlier US demands that it cease its aggressive activities there. They point to the controversial collision of a Chinese enforcement vessel and a Vietnamese fishing boat; China’s establishment of new administrative districts in the South China Sea and research stations on two Spratly features it occupies, and; the deployment of a PLA carrier strike group in the area. Timothy Heath, of Rand Corporation, said the increase in American military activity was partly due to the failure of diplomatic efforts to resolve these issues, leaving the US “no option” but to step up military activities to show “Washington is serious about maintaining the international status of the South China Sea … and signal its willingness to uphold its alliance commitments”. Others see the US move as specifically upholding the international order in the South China Sea. Reiterating the US commitment to a “rules-based order” in the sea, US Pacific Fleet Commander Admiral John Aquilino said China “must end its pattern of bullying Southeast Asians out of offshore oil, gas, and fisheries”. In this view, China has crossed a line by continuing to try to browbeat its neighbours even as they are preoccupied with the pandemic. The operations of a Chinese survey ship accompanied by coastguard vessels supposedly in others’ claimed waters near their exploration sites may have been the last straw. If so, and China continues in their eyes to intimidate its rival claimants, such “presence” operations may well become more common. US Navy warship transits Taiwan Strait as PLA starts live-fire drills Another theory is that the show of force has more to do with increased Chinese military activity viewed as threatening Taiwan. People’s Liberation Army aircraft have been observed at least six times this year close to Taiwan’s airspace, prompting Taipei to scramble its fighters as a precaution. Also, the Liaoning aircraft carrier strike group was seen twice last month in the vicinity of Taiwan, while the PLA’s Southern Theatre Command undertook an anti-submarine training exercise in the South China Sea in April. China explained that the exercises were in response to US military provocations and efforts to “gather intelligence”. The answer to “why now” may lie in the effects of the pandemic itself on the apparent readiness of the US military in the area. Apart from the sidelining of the Theodore Roosevelt carrier strike group due to a Covid-19 outbreak, in April, the US redeployed its front-line bombers from Guam to the US mainland ending the “continuous bomber presence” that it had trumpeted as a reassurance to allies in Asia. US Navy removes commander of virus-hit ship after scathing letter leaks Friends and allies seem increasingly worried that China is replacing the US as the regional hegemon and that the US is unlikely to come to their aid in a showdown with China over their claims in the South China Sea. According to this line of thinking, the US fears China may try to take advantage of the apparent lull in its military presence to intimidate its neighbours and has thus stepped up its deployments accordingly. The timing may also be influenced by the administration wanting to be seen as “tough on China” in the run up to November’s presidential election. None of these reasons are mutual exclusive. But in the end, if a clash occurs, it will not matter who was responding to whom – or even why – at least until the ensuing debate over who was to blame. Mark J. Valencia is an adjunct senior scholar at the National Institute for South China Sea Studies, Haikou, China Help us understand what you are interested in so that we can improve SCMP and provide a better experience for you. We would like to invite you to take this five-minute survey on how you engage with SCMP and the news.