President Donald Trump has unveiled what he calls a “massive” new trade and investment agreement with Japan, touting it as a major economic victory for the United States. But the deal—announced as complete—still faces an uncertain path forward, as Japan’s fractured parliament, the Diet, must decide whether to approve key provisions.
The agreement, revealed just ahead of Trump’s self-imposed August 1 deadline to impose steep tariffs on Japanese imports, includes a $550 billion Japanese investment in U.S. sectors like energy, semiconductors, pharmaceuticals, and shipbuilding. Trump also announced major concessions from Tokyo, including a 75% increase in U.S. rice imports, 100 new Boeing jet purchases, and expanded access for American vehicles and agricultural goods. In return, Japanese goods will still face a 15% U.S. tariff, while American exports to Japan will face none.
“We just completed a massive Deal with Japan, perhaps the largest Deal ever made,” Trump posted on Truth Social. “This is a very exciting time for the United States of America.”
Diet Approval Still in Doubt
Despite Trump’s celebratory tone, the deal is far from finalized. Legal experts and lawmakers in Japan say the agreement may require ratification—either in part or in full—by both chambers of the Diet, where Prime Minister Shigeru Ishiba’s government is on shaky ground.
Ishiba’s Liberal Democratic Party (LDP) recently lost its majority in the upper house, after already falling into the minority in the lower chamber in 2024. The opposition, led by the left-leaning Constitutional Democratic Party of Japan (CDP), has been skeptical.
“We need to carefully scrutinize the content of the agreement to determine whether it is satisfactory and how it will affect the Japanese economy,” CDP lawmaker Kazuhiko Shigetoku told Newsweek. “We will decide our next steps after government briefings in the Diet.”
Shigetoku emphasized the need to balance support for free trade with protecting Japan’s national interest.
Ishiba Defiant Amid Calls to Resign
Despite growing pressure to step down following his coalition’s defeat in July’s Upper House election, Prime Minister Ishiba has pledged to remain in office to oversee implementation of the U.S. deal.
“The government was determined to protect national interests,” Ishiba said, framing the agreement as a way to boost jobs and global cooperation between the two allies.
Still, analysts say the political backlash at home is real. Voters have expressed frustration over rising prices and stagnant wages, and many see the Trump deal as favoring Washington over Tokyo.
“Trade talks with the U.S. are seen as a test of leadership,” said Kristi Govella, Japan Chair at the Center for Strategic and International Studies. “The Ishiba government is now fighting to control the narrative.”
Opposition Walks a Tightrope
Govella said the CDP and other opposition forces are under pressure to critique the deal—but not reject it outright. Blocking the agreement could trigger retaliatory tariffs from the U.S., potentially damaging Japan’s already fragile economy.
“They have strong incentives to criticize, but blocking the deal could backfire,” she said. “Higher tariffs would hit consumers hard, and opposition parties risk losing the support they’ve recently gained.”
Japan’s experience with opposition leadership from 2009 to 2012 has left voters wary. If critics are seen as undermining national interests, public opinion may quickly shift against them.
Surprising Praise from Some Corners
While opposition voices are voicing caution, some Japanese analysts have acknowledged the deal’s strengths. Kazuto Suzuki, a public policy professor at the University of Tokyo, said the agreement’s success came as a surprise—even to some in Ishiba’s party.
“Many expected negotiations to fail. The fact that they succeeded caught people off guard,” he told Newsweek. “Reducing tariffs on automobiles and parts to 15% is highly regarded.”
Still, Suzuki added that the deal does not erase the LDP’s election defeat or the mounting criticism of Ishiba’s leadership.
“It’s unlikely the Diet will reject the deal,” he said. “Doing so would bring higher tariffs and serve no one’s interest.”
A Balancing Act for Japan
President Trump has long criticized the U.S.-Japan alliance, particularly its defense and trade arrangements. This deal is being framed by the Trump administration as a reset—one that shifts economic leverage back to the United States.
But for Japanese lawmakers, the challenge lies in showing they’re not simply capitulating. They must demonstrate to voters that Japan’s economic sovereignty remains intact—even as Washington claims the lion’s share of the benefits.
“These agreements are vulnerable to domestic politics,” Govella said. “And Japan is in a very delicate position right now.”
What’s Next
The Diet is now reviewing the agreement’s terms, and it remains unclear how much of it will require formal approval. Although outright rejection appears unlikely, the path forward will test Ishiba’s ability to lead a minority government and hold his political coalition together.
As the U.S. and Japan navigate this next chapter, the future of one of the world’s most important trade partnerships hangs in the balance.
