Editor's Note: (Jeffrey W. Hornung is a political scientist at the nonprofit, nonpartisan RAND Corporation. The opinions expressed in this commentary are his.)
(CNN) This week's summit at Mar-a-Lago between President Donald Trump and Japanese Prime Minister Shinzo Abe should be routine diplomacy allowing for two allies to catch up and reaffirm strategies. In reality, it represents a crucial moment: Trump and Abe need the summit to go well.
The two leaders have much to discuss, but two issues will likely dominate the agenda.
One is North Korea. Coming just days before the summit between North and South Korea, and before Trump's own as-yet-unscheduled meeting with Kim Jong Un, the Trump-Abe summit is an opportunity to reaffirm a unified stance on keeping the "maximum pressure" sanctions intended to force Pyongyang to denuclearize and roll back its ballistic missile programs.
A second issue is tariffs. When Trump imposed tariffs on security grounds on steel and aluminum imports last month, he did not exclude Japan. After some discussions, he did, however, provide exclusions for South Korea, Australia, Canada and the EU, all US allies. The meeting is an opportunity to discuss this potential flashpoint and find a resolution.
Behind the scenes, there is even more at stake.
For Abe, the meeting is critical for promoting Japan's interests in North Korea. Because Abe has no scheduled summit with Kim Jong Un, there is a risk Japan may be left behind. Meeting Trump is an opportunity to directly advocate for keeping Japan's interests on the list of priorities. This includes ensuring that stopping the North's abduction of Japanese citizens remains a priority, along with denuclearization and abandonment of its ballistic missile program. At the bare minimum, it means getting Trump to agree that Japan needs to be present at any multinational negotiations.
Economically, Abe needs Trump to exclude Japan from the tariffs. Abe staked his administration on economic growth. Trump's tariffs threaten critical sectors. The summit is a chance for Abe to remind Trump of the value Japan brings to the American economy. Abe has already noted in parliamentary debate that Japanese steel products help US auto makers become more competitive by keeping their products cheaper for American consumers.
Trump also has vital interests at stake. Trump needs Abe because Japan commands attention in the region. Through its diplomatic heft, economic clout, and soft power, Japan serves as a counterweight to China in an uncertain environment where many countries question America's commitment.
Strategically, given its robust military capabilities and hosting of approximately 50,000 US military personnel, Japan remains a critical player for regional peace and stability. Although Japan is legally limited in how it can use its military forces, Japan is the most important US regional ally. Its cooperation is needed for virtually any activity the US seeks in the region. The US cannot afford to lose Japan as a trusted ally.
Economically, Trump needs Japan. Although Trump pulled out of the Trans-Pacific Partnership, he has asked US officials to explore the possibility of joining the 11-country modified version that Japan is leading. Once implemented, this pact will serve as a foundation for building a broad free trade area. If Trump seeks fairer and more reciprocal trade and investment relations with Japan, including a bilateral free trade agreement, Trump could take this opportunity to move the ball forward on trade.
And for both, politically, a summit could not have come at a better time. Both are dogged by political scandals at home and desperately could use a success in international diplomacy to show their electorate their leadership skills. But these stakes are higher for Abe. While other foreign leaders distance themselves from Trump's rhetoric, Abe has publicly backed Trump on many issues, even as Trump complains about Japan. With Trump's actions now appearing to come at the expense of Japan, Abe faces a situation where he is expected to capitalize on his relationship with Trump.
What is most surprising is that this is even an issue. The two have developed a close relationship. Not only was Abe the first foreign leader to meet Trump after his November 2016 victory, he was the first to meet Trump at Mar-a-Lago after becoming President. They also have frequent phone conversations and give each other gifts as signs of their friendship. The fact that Trump is treating Abe in a manner that creates an atmosphere in which the summit needs to go well is something few would have predicted even a few weeks ago.
It is hard to argue that the dynamics of the US-Japan relationship have not changed. After a year and half of relative stability, the allies are now forced to talk about difficult issues in which they have vested interests. As allies, and close friends, they could both benefit from reconfirming common goals and establishing a set of strategies to deal with the region's challenges.