The assassination of Shinzo Abe of Japan is reminder that President Trump’s worst policy move was killing the Trans Pacific Partnership on his third day in office. The trade deal, conceived with the help of the era’s most visionary world leader, Prime Minister Abe, would have become a major tool to confront Communist China. 

Felled this morning, Abe was a Japanese patriot who envisioned a return of the Land of the Rising Sun to the center of the world’s power structure. He loved America and was a tireless promoter of alliances between free countries to resist the totalitarian regimes that oppose them. 

Abe regained the Japanese premiership in 2012, at the same time that Xi Jinping was made general secretary of China’s Communist Party. Abe detected the dangers posed by Mr. Xi’s China earlier than anyone in the free world. He saw TPP as a tool to confront that danger head on.

The pact among 13 countries across the Pacific region was signed by the participants, including President Obama and Abe, in 2016. A year later, as one of his first acts in office, Mr. Trump walked out of the TPP. There were legitimate reasons to scoff at the deal, chief among them its mind-numbing complexity. 

Following details of the Obama-era TPP negotiations with Japan and others was an onerous task. A friend who is an official in the Japanese foreign ministry was my favorite guide, but even his detailed reports failed to encompass the deal’s ins and outs. Auto unions in America, Japanese beef ranchers, Canadian farmers — all used political pressure points to derail the nigh interminable talks. 

Abe became the top facilitator, investing enormous political currency in convincing Japan’s powerful pressure groups to compromise. Beyond economic benefits for his country, Abe strongly believed that completing the deal would build a Pacific economic bloc to counterbalance Beijing, which he saw as a menace to Japan and the free world. 

Yet, when Mr. Trump withdrew from the deal, Abe didn’t sulk. Instead, he jumped the line to become the first world leader to congratulate the president-elect. The two leaders’ love of golf led to their bonding at Mar-a-Lago. Abe was even careful to serve burgers, rather than the traditional Japanese fare, to satisfy the visiting American president’s unique palate. The two became famous buddies. 

At the same time Abe refused to take no for an answer on his pet trade deal. With Japan as the remaining TPP’s largest economy, he turned to Australia and other members to resurrect the trade bloc. The new deal, including all the original members except America, was signed in March 2018 and was renamed the Comprehensive and Progressive Agreement for Trans-Pacific Partnership. 

Membership in the CPTPP is now seen as a prize for major and mid-size economies. Even the communist mandarins at Beijing applied last year for membership. So did Free China, South Korea, Thailand, Ecuador, and Britain. Although situated on the Atlantic, post-Brexit Britain could benefit from amping up its trade with the bloc’s Pacific powerhouses. 

Despite all our presidents’ tendencies to undo their predecessors’ policies, President Biden is yet to rejoin the trade deal out of which Mr. Trump cut America. America’s major unions, so beloved by Mr. Biden, might have something to do with it. The geopolitical importance and economic benefits of a cross-Pacific trade deal must overcome such considerations. 

To honor Abe, whose vision America must cherish, Washington would do well to resurrect its 2016 membership in the pact. The only new condition it should add for acceding to the CPTPP: Keep Communist China out and allow all free countries in — including, most urgently, the Republic of China at Taiwan.