Abe moved with impressive speed to get on Trump’s good side as soon as the US election results were in. He called him the following day and visited him at Trump Tower 10 days later, determined to establish a personal relationship with an incoming president whom neither he nor anyone else in Japan’s leadership circles knew well, if at all.

During their Trump Tower conversation the two leaders seem to have bonded, chatting for an hour and a half, 30 minutes longer than had been scheduled. When Abe exited Trump Tower he told the waiting Japanese press corp that the conversation convinced him that Trump ‘is a leader I can trust’.

Abe arrived in Washington in early February 2017, the second foreign leader after UK Prime Minister Theresa May to have a summit with the newly inaugurated President and the first to be invited to ride with him on Air Force One to Florida for a weekend at his Mar-a-Lago resort. 27 holes of golf, lunches and dinner gave Abe ample opportunity to share his views with Trump. All indications are that Abe did most of the talking — about China, North Korea, Japan’s defence policy, and how investments by Japanese corporations in the United States had created hundreds of thousands of jobs for US workers.

Abe’s charm offensive appears to have paid large dividends. Trump found in Abe the leader of an important allied nation who was not criticising his immigration policy or his desire to develop a personal rapport with Vladimir Putin, and whose enthusiasm for working closely with Trump seemed genuine. There was not anything Trump said to the press or that was in the two leaders’ joint communiqué that echoed the critical views he had voiced about Japan during the campaign.

Abe set out for Washington and Mar-a-Lago intent on accomplishing what every Japanese prime minister since the end of World War II has understood to be the most vital task of Japanese foreign policy: to ensure the stability of the US–Japan alliance.

During the eight years of the Obama administration Abe emphasised the shared US and Japanese commitment to values of democracy, freedom and human rights, and to sustaining a liberal international order and strong multilateral institutions. But that was then.

Now, the United States has elected a president who has said that he rejects the central role the United States has played in maintaining the post-war international order in favour of an ‘America First’ foreign policy. Abe lost no time to adjust his rhetoric and his strategy to meet the new situation.

Abe’s actions underscore the reality that when it comes to protecting its national security, Japan has no option but to do whatever it takes to forge a close relationship with the US President, whoever she or he might be. This is also a useful reminder of how different the situation faced by Japan is compared to that of the United States’ European allies.

Germany sits inside the EU which, whatever its problems, is a community of (mostly) like-minded states. The United Kingdom after Brexit will no longer be part of the EU but its people will continue to live in a region of economically advanced and democratic states.

Japan by contrast is an outlier in its region, a democracy that counts among its closest neighbours three autocracies (or worse): China, North Korea and Russia. All are nuclear weapons states. Its other close neighbour South Korea is a democracy, but its relations with Japan are strained by tensions emanating from the history of Japanese colonisation.

The most important challenges facing the United States and Japan are not how to manage the bilateral relationship but rather how to coordinate policies to deal with North Korea’s nuclear quest, China’s activities in the East China and South China Sea, and with changes taking place in the global economy. Japanese heaved a collective sigh of relief when Abe returned home unscathed from his summit with Trump.  But there is little comfort to be taken in knowing that the bilateral relationship is basically in good shape if the world around it is in turmoil. That turmoil shows no sign of quieting down.

Abe has responded to this situation with the kind of flexibility that has been characteristic of his years in office and that few of his critics expected when he became Prime Minister for the second time in 2012. He has not gone back to Yasukuni Shrine since his 2013 visit, which triggered strong criticism from Beijing and Seoul and drew an admonition from a ‘disappointed’ United States. He has backed away from his earlier support for a major revision of the controversial Article 9 of Japan’s constitution, and from the position taken by the LDP in its 2012 constitutional revision draft. His proposal now is to keep the existing two clauses in Article 9 as they are and add a third recognising the legality of the Self Defense Forces.

Well aware that the alliance with the United States is essential to maintaining a balance of power in East Asia, Abe has been careful not to say anything to offend Trump. But he is not putting all of Japan’s eggs in the US basket. Strengthening security relations with Australia, Southeast Asia and India, siding with the United States’ European allies on the Paris climate accord, seeking an agreement with Russia on the contested northern islands issue, and most recently signalling to China Japan’s interest in participating in the Belt and Road Initiative are part of a broad based strategy to secure Japan’s interests in an increasingly uncertain international environment.

Japan’s foreign policy since Commodore Perry’s black ships entered Tokyo Bay in 1853 has been guided by a determination to keep in step with the ‘currents of the times’. Now that Trump is in office it is unclear where those currents are leading. Abe has succeeded in getting Trump to drop his campaign rhetoric about Japan and has gotten their relationship off to a good start. But from what we have seen of the way Trump treats allies and disparages international agreements and institutions it would be foolish to believe that they necessarily will remain on an even keel, or to assume that Abe thinks they will.

Gerald Curtis is Burgess Professor Emeritus of Political Science at Columbia University.