Who signed this treaty?

 Controversy over the U.S.-Japan Security Treaty

     “The most important thing to note from his [Trump's] comments is that the United States is no longer committed to defending Japan, South Korea or Taiwan,” said Robert Dujarric, co-director of the Institute of Contemporary Asian Studies at Temple University’s Tokyo campus [and APP member]. -- South China Morning Post, 3/10/25

By Takuya Nishimura, APP Senior Fellow, Former Editorial Writer for The Hokkaido Shimbun

The views expressed by the author are his own and are not associated with The Hokkaido Shimbun
You can find his blog, J Update here.
March 10, 2025. Special to Asia Policy Point

On Thursday, March 6, U.S. President Donald Trump complained to reporters in the Oval Office that the Japan-U.S. Security Treaty was imbalanced and unfair. His remarks followed his accusation that European countries were "ripping off" the United States in trade while failing to pay enough for their own national security.
 
Prime Minister Shigeru Ishiba responded by stressing that that treaty requires Japan to maintain bases in Japan for the U.S. military. Trump’s “America-first” attitude is now shaking the relationship between the U.S. and its top ally in the Indo-Pacific.
 
To the White House reporters, Trump insisted that the U.S.-Japan Security Treaty was not reciprocal. “I love Japan. We have a great relationship with Japan, but we have an interesting deal with Japan that we have to protect them, but they don’t have to protect us,” he said. “They make a fortune with us economically,” said Trump, who then asked who had made that deal.
 
The answer to his question is: U.S. Secretary of State Dean Acheson and Japanese Prime Minister Shigeru Yoshida. On September 8, 1951, they signed the Security Treaty after the San Francisco Peace Treaty ceremony. The Peace Treaty ended the legal state of war between Japan and the Allied Powers and their military occupation of Japan.  The Security Treaty addressed U.S.-Japan security arrangements going forward.
 
The Japan that signed these Treaties was and remains governed by a constitution that came into effect in 1947. Article 9 of the constitution renounces “war as a sovereign right of the nation and the threat or use of force as means of settling international disputes.” This has been interpreted as prohibiting the exercise of collective self-defense. Japan thus recognizes the Security Treaty as obligating the U.S. to defend Japan. This has been the mutual understanding of both countries since 1951. Trump is probably unaware of this history and expressed his skepticism in the context of an economic transaction.
 
“Each party recognized that an armed attack against either party in the territories under the administration of Japan would be dangerous to its own peace and safety and declares that it would act to meet the common danger in accordance with its constitutional provisions and processes,” says Article 5 of Japan-US Security Treaty.
 
Furthermore, under Article 6 of the Treaty, “[f]or the purpose of contributing to the security of Japan and the maintenance of international peace and security in the Far East, the United States of America is granted the use by its land, air and naval forces of facilities and areas in Japan.”
 
Ishiba replied to Trump’s complaint during discussions with the budget committee of the Upper House: “Japan does not have an obligation to protect America. That’s true. But Japan has a duty to offer America the bases in Japan, which no other country owes. It is not necessarily the relationship in which the U.S. unilaterally protects Japan and Japan is unilaterally protected by the US,” Ishida explained, referring to Article 6.
 
Trump had raised the same argument in his first term. Japanese officials believe Trump will use this assertion as a card to play in bilateral negotiations over economic issues, including trade and tariffs. “I am confident that the U.S. will live up to its obligation in the Japan-U.S. Security Treaty using every kind of capability, including nuclear,” said Chief Cabinet Secretary, Yoshimasa Hayashi.
 
Ishiba is a realist. Maybe he senses that Trump is serious about abandoning American security obligations in Asia as he is now doing in Europe. Ishiba has been advocating revision of the Japan-U.S. Security Treaty before Trump entered his second term. In his essay for the Hudson Institute in 2024, Ishiba wrote: “The time is ripe to change this ‘asymmetrical bilateral treaty.” Although he said he wants “to raise the Japan-US alliance to the level of the US-UK alliance,” the rapid evolution of Trump’s America First security strategy suggests that Japan would be better off with a “separate” arrangement rather than one that is equivalent to whatever the relationship is between the UK and the US.
 
Trump has been questioning the U.S. relationship with Japan. He has accused Japan of devaluing the yen against the dollar. “I’ve called President Xi; I’ve called the leaders of Japan to say you can’t continue to reduce and break down your currency. You can’t do it, because it’s unfair to us,” Trump told reporters, including China as another offender.  Trump insisted that the easiest way to solve the currency valuation problem (if there is a problem) would be through tariffs.
 
After the U.S. President’s comment, the yen briefly climbed from 150 yen per dollar to 148 yen. “We are not adopting a policy to weaken the (Japanese) currency. If you recall our foreign exchange market interventions in recent years, you can understand what I mean,” the Minister of Finance, Katsunobu Kato, said in a press conference.
 
It is undeniable, however, that the Japanese government is getting nervous about Trump’s aggressive announcement on tariffs. The U.S. president keeps raising his demands on trade policy, including a 25% tariff on foreign steel and aluminum, additional tariffs on cars and the introduction of “reciprocal” tariffs. And he is vocal in demanding defense spending increases.
 
The former Governor of the Bank of Japan, Haruhiko Kuroda, who led the Bank to adopt an ultra-low interest policy, emphasized the need to fix the “misunderstanding” of the U.S. President. "The BOJ is not intentionally guiding the yen lower with monetary policy. If there's any misunderstanding on that point, it needs to be addressed," Kuroda said in a TV program.
 
It is uncertain whether the U.S. President is aware of the history of the Security Treaty – which imposes requirements for Japan that continue to this day – or of the responses to his comments from Japanese officials. And it is uncertain whether Trump’s interests are solely for economic reasons or as part of a larger geo-political realignment.