The Japanese media spent as much time debating the limitations of the current constitution as celebrating its achievements. In many parts of the country, commemorative events were overshadowed by protest gatherings of citizens voicing opposition to the prospect of possible constitutional change.

The timing of the anniversary was ironic. November was also the month when committees in both houses of the Japanese parliament re-opened debate on constitutional revision. So far, this debate has remained cautious and low-key, but has been given new meaning by the circumstances in which it is being conducted. The July 2016 elections for the first time gave the current administration and its political allies the majority in both houses of parliament needed to alter the constitution.

Prime Minister Shinzo Abe himself has long dreamed of constitutional overhaul as part of his broader objective of erasing the traces of what he calls ‘the post-war regime’. Earlier this year he voiced his hopes of accomplishing constitutional revision while he is in power. Impending changes within the ruling Liberal Democratic Party (LDP) will allow the party’s leader to remain in power for three terms rather than the current two, opening the way for Abe to remain prime minister into the 2020s. So the time-frame for him to achieve this long-cherished dream is now likely to be expanded.

Most importantly, with the election of Donald Trump as US president, Japan’s cautious but persistent moves towards constitutional change are unfolding in the context of momentous transformations on the world stage. During his election campaign, Trump repeatedly expressed his iconoclastic views on US engagement with allies in Asia and elsewhere, of which Japan is perhaps the most important. His proposed approach (in the president-elect’s own words) is to say to such countries, ‘congratulations, you will be defending yourself’.

Following his shock election, commentators rushed to the airwaves to reassure themselves that Trump will be surrounded by sober advisors who will restrain his more alarming political impulses. But the lesson of history, from Benito Mussolini to Rodrigo Duterte, is that if populists come to power promising to do alarming things, we should be prepared for the possibility that they will actually do them. To date, though some far-right commentators in Japan have welcomed Trump’s election as a ‘once in a lifetime’ chance to rewrite the constitution, Japanese media has been surprisingly quiet about the implications of a Trump administration for political change in Japan.

But there can be no doubt that, behind the scenes, the outcome of the US election is already having a major impact on the way that Japanese politicians, officials and military strategists think about the future. This impact comes not from any clear vision of the policies that a Trump administration is likely to implement, but rather from the uncertainties that now surround US intentions. The assumptions on which Japan’s entire post-war order rather complacently rested suddenly look extremely shaky.

These uncertainties have ramifications across the region. Under Obama and his predecessors, the United States played a very active role in persuading Japan and South Korea to work together despite the continuing tensions between the two countries, particularly over the legacies of colonial rule. One outcome of that pressure was the December 2015 joint statement by the Japanese and South Korean foreign ministers on the contentious ‘comfort women’ issue.

But even with US pressure and even before Trump’s election, the difficulties of bridging the divide were obvious. The December 2015 accord was accepted by the South Korean government but roundly condemned by large sections of public opinion, making it one of many factors that accelerated a dizzying plunge in South Korean President Park Geun-hye’s popularity ratings. As new scandals deal a death blow to the Park regime’s legitimacy in the eyes of the public, South Korea has entered a phase of political crisis: a crisis that compounds the anxieties facing East Asia.

The Japanese government’s 1955 White Paper on the Economy famously pronounced the end of the post-war era. But in political terms, core elements of the post-war — enshrined above all in the constitution — survived. Following the fall of the Berlin Wall and the death of Emperor Hirohito in 1989, many observers spoke of the end of Japan’s ‘long post-war’. 2016 has surely become the year that marks the end of the 70-year very long post-war.

East Asia has entered a new age of political instability, where the risks of competitive military expansion and diplomatic frictions are greater than they have been for decades. There are very many people in countries across the Asia Pacific region who still cherish the hope for peace and democracy evoked by the post-war Japanese constitution. The challenge they now face is to find new ways to recreate and promote that hope in the very uncertain era that we are entering.

Tessa Morris-Suzuki is an ARC Laureate Fellow based at the School of Culture, History and Language, at the College of Asia and the Pacific, The Australian National University.

This article is part of an EAF special feature series on 2016 in review and the year ahead.