IT IS one of the spectacles of soldiering in the democratic world: the moment when a four-star general fields a hard question from a lowly grunt. The chairman of the joint chiefs of staff, General Joseph Dunford, had his turn while visiting US marines in Australia’s tropical north this month. As ceiling fans stirred the soupy air of a mess hall in Darwin, a marine asked how conflict with North Korea might unfold, and what had changed since the Korean war, so that: “We don’t get as many casualties as we did in the 1950s.” The general, America’s most senior uniformed officer, replied that he is “painfully aware” of that history, because his father fought in Korea as a marine rifleman. He assured the assembled marines and their hosts, burly Australian officers in berets and slouch hats, that isolating North Korea diplomatically and economically remains the priority. Then he offered a warning. For all America’s modern weaponry, any new Korean fight would be “nasty”. If troops wake each morning believing this might be their last day at peace, he went on, they will be mentally “in the right place”.

The marines in Darwin—an advance party preparing for over a thousand comrades to arrive in April for six months’ training in Australia’s crocodile- and snake-infested Top End—are entitled to ask about war and peace. Their home base in Japan would quickly be dragged into a Korean fight. In Australia they serve as a tripwire force, deployed under an agreement reached in 2011 during President Barack Obama’s “Asia rebalance”. In these war-clouded times, there are military reasons to cherish this barren outpost. The training opportunities are “spectacular”, says a colonel. “You can fire just about anything you want.” But to an extent that might surprise Americans back home, the marines in Darwin matter most as soldier-diplomats.

They are a flesh-and-blood guarantee to a treaty ally that America First does not mean America Alone. They are also a rebuke to a rising China that wants to dismantle an American-led order which has prevailed in the region since the second world war. A nine-day tour of Asia aboard General Dunford’s military jet is filled with such political moments. Though headlines shout about nuclear stand-offs with North Korea, commanders are as worried by a colder Asian clash: a long-term contest for influence with China.

The marine rotation in Darwin sends a “powerful message” of enduring commitment to allies, amid “concerted” efforts “in some quarters” to portray America as a declining Pacific power, says General Dunford, as his blue and white plane is refuelled. He does not name China, but does not need to. The general, a combat veteran dubbed “Fighting Joe” for his hard-driving ways during the invasion of Iraq in 2003, had just told his marines that America’s great defining strength lies in its networks of alliances. As a result, his country’s credibility as an ally is “the first target” for any power “trying to undermine the United States politically, diplomatically and from a security perspective”.

Seen from Asia, America is an unhappy, distracted democracy locked in competition with a confident, single-minded autocratic regime in China. A recent Australian government white paper expresses hope that America will continue to lead a global “rules-based order”, even as Australia seeks “strong and constructive ties” with China, its largest trading partner. But the same paper sadly notes “greater debate and uncertainty” among Americans about the costs and benefits of that leading role. “Without America”, an essay by Hugh White, an Australian writer and former government strategist, has shaken elite opinion by predicting that the Asian contest comes down to a test of resolve, which “America will lose, and China will win.”

American officers and diplomats reject this, noting that 60% of the American air force and almost as great a proportion of the navy is now in the Pacific, including the most modern weapons platforms. They point to the clamour from allies for American ship visits, joint exercises and intelligence-sharing. But they do not deny that America’s democratic model is being tested, just as much as its strength of arms.

Allies want a rules-based order, says General Dunford. “They don’t want might to equal right.” During another stop he argues that liberal democracies gain an edge over autocracies by educating and giving the power of initiative to non-commissioned officers—the sergeants and senior enlisted troops who wield real clout in America’s armed forces—creating flexible units that adapt to the “chaos of combat.”

China has long invested in planes, ships and other weapons needed to deny America easy access to its neighbourhood. But a more recent political challenge may prove as serious. Chinese generals and political leaders chide American counterparts that its alliances are a holdover from the cold war and an attempt to hold China down.

Captain Joseph Trench Niez, the 28-year-old navigator on a B-52 bomber stationed on the Pacific island of Guam, enthuses about reassuring allies with sorties around the Philippines and Japan. Three generations of pilots have flown his B-52, a scarred old whale of a plane built in 1960. It has seen service in wars from Vietnam to today’s conflicts in Syria and Afghanistan, as shown by fresh bomb stickers on its nose. That history is “incredible”, he says.

It is that earnest certainty that America stands for right as well as might that China is now challenging. American officials retort that China uses economic coercion to turn neighbours into tribute nations. The Asian power contest is increasingly a contest of values. America’s generals are not ready to concede. They must hope their country is up for the same fight.