The U.S.-British alliance – a bond forged in blood in two world wars, is the so-called “special relationship” most people fawn over. However, there might be one other special bond – forged after World War II, turning bitter enemies into the closest of allies – that is even more important today: the one between America and Japan.

Japanese Prime Minister Shinzo Abe began two days of meetings with President Trump at the president’s Mar-a-Lago estate in Florida Tuesday. Just looking over the amount of issues these two world leaders will need to discuss, their “special relationship” will be tested in a historic manner.

At the start of their meeting, President Trump announced, with Abe at his side, that North and South Korean leaders – who are holding their own summit April 27 – will seek to finally reach an agreement to formally end the Korean War, which was halted with an armistice in 1953.

“We’ve also started talking to North Korea directly,” President Trump said. “We have had direct talks at very high levels, extremely high levels, with North Korea. And I really believe this allows good will, that good things are happening.”

The issue of what to do about North Korea is center stage for the Trump-Abe meeting, and is the most likely reason Japan’s prime minister crossed the Pacific to meet with President Trump in short order.

The timing of this visit is clearly critical. When President Trump recently agreed to a summit with North Korean dictator Kim Jong Un, Japan was surely taken by surprise. Now Abe must be worried that America could be going too far, too fast, in trying to achieve some sort of agreement with the North.

And when one factors in South Korea’s recent peace overtures to North Korea since January, there is a sense in Tokyo that Japan’s own security interests are slowly being forgotten.

Over the last several weeks, I have spoken to several Japanese government officials who have been very clear in voicing some frustration. As one official explained: “We don’t want to be left behind” when it comes North Korea.

The official continued: “It was Japan that had two (North Korean) missiles overfly our country – a threat that really has awoken the Japanese public to the dangers presented by North Korea. If one of these missiles had any sort of guidance problem or malfunctioned and crashed into our territory it would have been Japanese citizens who paid the price – with their lives. We want to make sure we are consulted, that we know America’s intent, as well as South Korea’s. We don’t demand a seat at the table – we just want to know what is going on at the table.”

White House and other U.S. government officials I have spoken to were very clear that they have excellent communication with their Japanese counterparts and have heard their concerns. Japan’s unique security situation – being so close geographically to North Korea – is always part of Washington’s strategic calculus, whatever happens with the Kim regime, officials told me.

One State Department official was very candid with me: “Japan should rest easy. We would never, ever, conclude any major agreement with North Korea of major importance without consulting our allies – and that means Japan, South Korea and others. Our allies in Asia, and the bigger Indo-Pacific region, are of the prime importance to us. We would never harm those relationships by concluding any agreements that could change the regional dynamics dramatically without knowing where they stand.”

But North Korea is not the only security issue America and Japan share, and, of over the long term, a much bigger challenge has arrived: a rising China.

Indeed, Washington and Japan, always considered Beijing the biggest joint challenge the alliance faced – until North Korea began heavy testing of missiles and a nuclear weapon last year.

Both the U.S. and Japan need to make sure they can resist China’s aggressive and bullying tendencies – whether in the East China or South China Seas. And America and Japan must make sure allied defensive capabilities are able to negate and deter Beijing’s rising military might in any domain and across the wide expanses of the Indo-Pacific region.

Then there is the complex issue of trade. President Trump has called out Japan and its trade practices. He has labeled these practices unfair because they take jobs away from Americans.

With Washington leaving the Trans-Pacific Partnership (TPP) trade agreement, there seems to be some daylight in the alliance on this critical issue. However, with President Trump possibly open to rejoining TPP – and knowing that Prime Minister Abe has been pressing the administration hard to rejoin the agreement – there is a possibility of a breakthrough on this core issue during their meetings.

It seems clear Trump and Abe have much to discuss, with a changing security and economic landscape in Asia that will test this alliance time and time again in the months and years to come.

But as someone who has traveled to Japan extensively and worked with many Japanese colleagues in the realm of security issues and publishing over the years, I can honestly say that Tokyo could be no better partner or friend to Washington.

Perhaps a Pentagon official I know well summed it up best: “We have no better ally than Japan. In peacetime they are our most valued partner and friend. And in a crisis, I know we can count on them to stand with us. There is no nation I trust more.”