After eight years of dealing with America’s self-styled “Pacific president”, Asian leaders will soon have to work with a new administration.
 Barack Obama’s last trip to Asia was always going to have a sense of nostalgia and finality.
 He received a farewell round of applause from G20 leaders in China and South East Asian leaders paid tribute to him Laos. Myanmar’s Aung San Suu Kyi thanked him for nudging her country towards democracy.
 From White House staff to Obama himself, his regional swansong capped the “pivot to Asia” policy of his eight-year term and was thick with a sense of an administration winding down. 
 “My hope and expectation is my successor will in fact sustain this kind of engagement,” Obama said as he rounded off his trip in Laos.
 During his two terms in the White House, Obama has tried to shift America’s focus away from Middle East quagmires and toward rapidly growing Asia.
 He has mended relations with Myanmar, Vietnam and Laos, while bolstering regional blocs. But questions hang over whether Obama’s pro-Asia stance will be sustained.
 Donald Trump has called into question the mutual defence treaties with Japan and South Korea, which have been the cornerstones of US policy in Asia since World War II.
 But overall the Republican nominee’s strategic thinking on foreign policy has been hard to gauge, and Asian diplomats readily admit they have struggled to find interlocutors in his campaign team.
 Trump’s rival Hillary Clinton, as Obama’s former top envoy, was intimately involved in creating and implementing the “Asian pivot”, which has bound Washington tighter to the region and provided a counterpoint to China’s dominance.
 As secretary of state, Clinton regularly courted Beijing’s ire on the South China Sea – which she described as part of the US’s “national interest” – as well as its human rights record.
 Clinton, however, opposes the ratification of the 12-member Trans-Pacific Partnership, which notably omits China.
 The South China Sea will likely represent one of the biggest foreign policy challenges to the next US president.
 During Obama’s time in the White House, China has aggressively asserted its territorial claims over the vital waterway.
 Obama has insisted on America’s right to fly or sail where it likes, but he has also indicated that the US will not go to war over a remote islet, shoal or reef.
 Under this world view, territorial integrity, the rule of law and upholding treaty obligations are desirable, but not necessarily worth risking a great power conflagration or the blood of US sailors.
 He has also been wary of escalating disputes with actors who have a more immediate interest at stake.