The much anticipated first meeting between presidents Donald Trump and Xi Jinping ended in smiles all around at Mar-a-Lago, Trump’s luxury private club in Florida. That’s good news for Australia. When China and the United States get along, political leaders and public servants in Canberra and capitals across the Asia–Pacific can breathe more easily.

Though Trump tweeted in advance that talks with China’s president would be ‘very difficult’, it was evident that he was determined to have a positive meeting. Gone—at least in public—was any trace of Trump’s previous combative rhetoric about China ‘raping’ America on trade or building a ‘massive military complex’ in the South China Sea. Trump was a welcoming and gracious host. Xi, in turn, was keen to demonstrate that the US–China relationship is stable. ‘We have a thousand reasons to get China-US relations right, and not one reason to spoil the China-US relationship’, he told Trump.

Undoubtedly, the upbeat coverage of the visit in the Chinese press and optimistic statements by senior Americans are significant. The world’s most consequential bilateral relationship has undergone a positive re-set after a rocky period. However, Trump’s decision to order missile strikes on Syria, which were executed while he dined with Xi in Florida, sent a stark message not only to Syria’s president Bashar al-Assad but undeniably to Xi Jinping as well.

The chemical weapons attack in Khan Sheikhoun that killed nearly a hundred civilians, including children, took place 60 hours before Xi’s plane landed in Florida. Trump could have delayed the missile strike on Syria until Xi’s 24-hour visit was over. But he chose not to, putting Xi in an awkward position. The message was clear: the United States continues to view itself as the global power with the right to take unilateral military action.

Over the past six years of atrocities in Syria, China has vetoed six United Nations Security Council resolutions specifically targeting the Assad regime. While Xi was in Florida the spokesperson for the Ministry of Foreign Affairs stated that China opposed the use of force, but stopped short of condemning unilateral American actions—as Beijing has done in the past and most probably would have done this time too had Xi not been spending the night in Florida.

Chinese state-run media outlets have only briefly reported on the US strikes on Syria and were initially entirely silent about the implications of the strikes for North Korea and its refusal to halt its nuclear program. The tabloid Huanqiu Shibao (Global Times), known for its nationalistic stances, initially tried to offer public commentary. It stated in an editorial on Saturday that Trump wanted to prove that he cannot be dismissed as a ‘businessman president’ and that ‘he can use military force when necessary’. However, the Chinese-language version of the editorial was removed without explanation from the newspaper’s website the following day. Finally, on Monday a new Chinese-language editorial was published discussing whether North Korea would become ‘the next Syria’.

Though Trump’s decision to swiftly authorise the missile strikes obviously sends a strong signal to Pyongyang, it’s equally profound for Beijing: the United States wants China to use all possible means to halt North Korea’s nuclear program. In fact, one of the only pointed statements in the otherwise bland White House briefing of the Trump–Xi meetings was Secretary of State Rex Tillerson’s statement: ‘(we are) prepared to chart our own course if this is something China is just unable to coordinate with us’.

China has persistently called for multilateral talks to peacefully resolve the stand-off on the Korean peninsula and staunchly opposed use of force. As the North’s largest source of food and energy, China certainly is in a unique position to exert increased pressure on Pyongyang. But Beijing isn’t willing to let the North Korean regime collapse for several reasons, among others for fear of the millions of refugees who would likely spill over the border into China.

A unilateral decision by the United States to destroy North Korean nuclear facilities would be extremely risky. The challenges of the Korean peninsula and Syria cannot be compared. Whereas Syria could be targeted without fear of immediate retaliation, North Korea has the capability to cause severe damage to South Korea and perhaps even to Japan. North Korean artillery units deployed along the demilitarised zone could devastate Seoul, situated a mere 50 kilometres from the North Korean border. Pyongyang’s nuclear arsenal and gradually growing missile force could cause catastrophic loss of life if not completely neutralised in an initial US strike.

In sum, while the optimistic mood in which Trump bade Xi farewell—with the promise to visit China soon—is good news, Xi Jinping has returned home with a clear warning: don’t underestimate Trump’s desire to get tough on North Korea.