The leaders of America and Japan unveiled a lengthy list of defense agreements Wednesday in what U.S. President Joe Biden called “the most significant upgrade in our alliance since it was first established.”

The two countries will improve their respective command-and-control systems, form an industrial council to build weapons together, network their missile defense systems with Australia’s and start a joint exercise with the United Kingdom, among other agreements. For the first time, America will also adjust its force structure in Japan to better work with Tokyo’s defense forces.

“This is about restoring stability in the region, and I think we have a chance of doing that,” Biden said at a Wednesday press conference with Japanese Prime Minister Fumio Kishida in the White House Rose Garden.

The subtext in Biden’s comment is China, which over the last 15 years has grown far more powerful and aggressive. The change has worried the U.S. that China is trying to push it out of the region, isolate allies like Japan and potentially take Taiwan — which China considers a rogue province — by force.

There may be no better case study than Japan. In the last several years, it’s doubled a cap on defense spending from 1% to 2% — a share it plans to spend by 2027. Japan also entirely revised its national security strategy, scrapped limits on defense exports and bought weapons, such as the Tomahawk missile, that allow it to strike back if attacked.

Many of these changes altered Japanese defense policy that had been in place since after the Second World War, when Japan demilitarized and adopted a pacifist constitution.

“What Japan’s has been doing over the past few years is nothing short of astounding — just unthinkable even a few years ago,” said Toshi Yoshihara, a China expert at the Center for Strategic and Budgetary Assessments. “And I credit the Chinese for that. No one has done more to get Japan to modernize and get serious about defense than China itself.”

Speaking with reporters ahead of the event, senior administration officials said the new agreements won’t take effect for months.

Earlier in the week, defense officials from Australia, the United Kingdom and the U.S. said Japan and other countries may later join part of the AUKUS defense pact, an agreement to share nuclear-powered submarines and other defense technology. Any openings would be for AUKUS’ second pillar, which concerns advanced technology like artificial intelligence and hypersonic missiles.

“What we’re all focused on is demonstrating to our respective populations early victories on pillar two,” Australia’s Minister for Defense Industry Pat Conroy told Defense News in an interview.

Kishida is in the nation’s capital for a state visit — one of Washington’s top honors. He’s the fourth leader from the Indo-Pacific to do so during the Biden administration, and the White House cites that number as a sign of its commitment to the region.

Biden and Kishida will also meet later this week with Ferdinand Marcos, president of the Philippines, in the three countries’ first trilateral summit.

Noah Robertson is the Pentagon reporter at Defense News. He previously covered national security for the Christian Science Monitor. He holds a bachelor’s degree in English and government from the College of William & Mary in his hometown of Williamsburg, Virginia.

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