Jonathan Ernst / Reuters

Throughout his speech to a joint session of Congress Wednesday, Japanese Prime Minister Shinzo Abe cited continuities in the relationship between his country and the U.S. "Our alliance has lasted more than a quarter of the entire history of the United States," he noted. He mentioned his grandfather, Nobusuke Kishi, a former Japanese prime minister who helped forge the close U.S.-Japanese alliance that developed after World War II.

But in many ways, Abe's speech, and themes he propounded, tested the limits of generational turnover. How far have memories of the war receded? Has enough time passed that Japanese and Americans alike are comfortable with Abe's vision of reversing military limits in the post-war constitution the U.S. wrote for Japan? And will members of Congress forget the sometimes-tense U.S-Japan trade relationship of the 1980s and agree to a sweeping new free-trade agreement?

Abe—the first Japanese head of government to address a joint session of Congress—was born in 1954, nearly a decade after the war ended. His praise Wednesday for the late Senator Daniel Inouye as a beacon of Japanese-American achievement served as a reminder that there are no World War II veterans left in Congress. The prime minster opened with a lengthy reflection on the war, recounting a visit he paid to the World War II Memorial on the National Mall before his speech:

Pear Harbor. Bataan. Corregidor. Coral Sea. The battles engraves at the memorial crossed my mind and I reflected upon the lost dreams and lost futures of those young Americans. History is harsh. What is done cannot be undone. With deep repentance in my heart, I stood there in silent prayers for some time. My dear friends, on behalf of Japan and the Japanese people, I offer with profound respect, my eternal condolences to the souls of all American people that were lost during World War II.

While Abe's sentiments seemed heartfelt and extensive, he didn't make a great effort to delve into Japan's role in starting the war, nor its conduct during the fighting. He has come under heavy international criticism for visiting the Yasukuni Shrine, which memorializes fallen Japanese soldiers, including convicted war criminals. Abe also didn't mention "comfort women," the women forced into sexual slavery during the war. That the Japanese used them is not in historical dispute, but some members of the nationalistic wing of Japanese politics to which Abe belongs have denied it. This makes the issue a sensitive one for the prime minister, who finds himself caught between foreign demands and his political base. American politicians, including Senator Marco Rubio, have called on him to apologize, which he declined to do Tuesday.

Abe's nationalistic politics has also involved the promotion of a stronger national-defense policy. The post-war constitution sets out limits on the scope of Japan's military, but he has sought to loosen them, and on Wednesday vowed to continue efforts to expand Japan's Self-Defense Forces, citing their deployments in peacekeeping missions around the world. While the U.S. has been publicly supportive, many American observers worry that the military buildup could stoke tension in Asia. But Abe didn't mention by name the elephant in the room: China, whose own military expansion and efforts to claim disputed territory are a major factor in Japan's calculations. How to balance support for an ally with the need to maintain relations with China is a signal challenge of America's foreign policy in Asia.

After recounting his visit to the memorial, Abe embarked on a lengthy discussion of how American trade and aid, and especially the importation of American free-market capitalism, had rebuilt Japan after the war. "It was Japan that received the biggest benefit from the very beginning: The economic system that the U.S. has fostered by opening up its own markets and calling for a liberal world economy," he said.

The intended takeaway for members of Congress: It's time to put your votes where your capitalist rhetoric is, and move forward on the Trans-Pacific Partnership, a major free-trade deal involving a dozen countries on both sides of the Pacific. Abe is in Washington to negotiate with President Obama on the deal, and while they haven't reached a final agreement, both sides said there was progress. As Abe knows, a final deal will also have to win over Congress, and a good number of Democrats oppose it. Particular sticking points include Japanese resistance to cutting agricultural and American carmakers' complaints that the Japanese auto market is effectively closed to them.

Abe took a notably conciliatory tone on agriculture, remembering his own staunch defense of tariffs during negotiations for the General Agreement on Tariffs and Trade two decades ago. "I was much younger and like a bowl of fire, and opposed to opening Japan’s agricultural market," he said. "However, Japan’s agriculture has gone into decline over these last 20 years. ... In order for it to survive, it has to change now." But he made no mention of automobiles during his roughly hour-long speech.

Given Japan's two decades of economic stagnation, memories of the 1980s-era panic about Japanese takeover of American companies and landmarks have also faded—perhaps even dimmer than those of World War II. Abe received a warm welcome from Congress, with extended applause and generous laughter for his jokes ("I have lots of things to tell you, but I am here with no ability nor the intention to filibuster," he cracked at the outset). His hopes for congressional backing are premised on the most negative memories already having faded.

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