Title: Japan–United States relations
Content:  partially revived the old "Japan bashing" rhetoric from the 1980s by complaining about Japan engaging in "unfair" trade practices, rhetoric that many commentators viewed as "outdated" and "anachronistic." As president, Trump withdrew the United States from the Trans Pacific Partnership, which many viewed as a blow to Japan. Trump also repeatedly expressed his hopes of convincing Japan to dramatically increase its annual payments subsidizing U.S. military bases in Japan. However, despite the inflammatory rhetoric, Trump and prime minister Shinzō Abe had a somewhat cordial relationship, and succeeded in negotiating a bilateral trade deal in 2019 that lowered tariffs between the two nations. Abe's successors, prime ministers Yoshihide Suga and Fumio Kishida, have enjoyed good relations with current U.S. President Joe Biden.
Title: Japan–United States relations
Content:  Bush announced Japan was being removed from the list of countries the US was targeting with reprisal tariffs for what was considered unfair trading practices on the part of Japan. The decision was made on the recommendation of U.S. Trade Representative Carla A. Hills and was hailed by Japanese officials. The move also came at a time where the US had a $50 billion trade deficit with Japan, and congressional critics lambasted the move as premature. In January 1991, Bush launched the Gulf War in order to roll back Iraq's invasion of Kuwait. Japan was unable to send troops due to Article 
Title: Japan–United States relations
Content:  the world's second economic power after the United States. As a result however, both Japan and the United States would come to a head once more, this time economically, with a trade war between the two countries during the late 1980s and early 1990s, which culimated after the Japanese asset price bubble burst shortly after the signing of the Plaza Accord. Japan would eventually drop to third place in 2010 after China. From the late 20th century and onwards, the United States and Japan have firm and very active political, economic and military relationships. US government officials generally consider Japan to be one 
Title: Shōwa (1926–1989)
Content:  after the signing of the Treaty of San Francisco, which became effective on April 28, 1952. It restored the sovereignty of Japan. On the same day, the Security Treaty Between the United States and Japan was signed as Cold War tensions rose; it was later replaced by the 1960 Treaty of Mutual Cooperation and Security Between the United States and Japan. The 1960 treaty requires the U.S. to protect Japan from external aggression. It allows United States forces to be stationed in Japan. Meanwhile, Japanese ground and maritime forces deal with internal threats and natural disasters. This established the U.S.–Japan 
Title: Japan–United States relations
Content:  non-relations with China look like he had been played for a fool. The following month, the government was again surprised to learn that, without prior consultation, Nixon was imposing a 10 percent surcharge on imports, a decision explicitly aimed at hindering Japan's exports to the United States, and was unilaterally suspending the convertibility of dollars into gold, which would eventually lead to the collapse of the Bretton Woods System of fixed currency exchange rates. The resulting decoupling of the yen and the dollar led the yen to soar in value, significantly damaging Japan's international trade and economic outlook. These shocks of 
Title: Japan–United States relations
Content:  Notable outpourings of United States congressional and media rhetoric critical of Japan accompanied the disclosure in 1987 that Toshiba had illegally sold sophisticated machinery of United States origin to the Soviet Union, which reportedly allowed Moscow to make submarines quiet enough to avoid United States detection, and the United States congressional debate in 1989 over the Japan-United States agreement to develop a new fighter aircraftthe FSXfor the Japan Air Self-Defense Force. The United States Government halted the purchase of Toshiba products for three years in retaliation.
Title: U.S.–Japan Alliance
Content:  The U.S.-Japan alliance was forced on Japan as a condition of ending the U.S.-led military occupation of Japan (1945-1952). The original U.S.-Japan Security Treaty was signed on September 8, 1951, in tandem with the signing of the San Francisco Peace Treaty ending World War II in Asia, and took effect in conjunction with the official end of the occupation on April 28, 1952. The original Security Treaty had no specified end date or means of abrogation, allowed US forces stationed in Japan to be used for any purpose without prior consultation with the Japanese government, had a clause specifically authorizing US troops to put down domestic protests in Japan, and did not commit the United States to defend Japan if Japan were to be attacked by a third party. Because the original treaty was so one-sided, it was the target of protests in Japan throughout the 1950s, most notably the "Bloody May Day" protests of May 1, 1952, and Japanese leaders constantly entreated with US leaders to revise it.
Title: Trade policy of Japan
Content:  Between 1960 and 1964, Japan incurred annual trade deficits (based on a customs clearance for imports) ranging from US$400 million to US$1.6 billion. The era of chronic trade deficit ended in 1965, and by 1969, with a positive balance of almost US$1 billion, Japan was widely regarded as a surplus trading nation. In 1971 the surplus reached US$4.3 billion, and its rapid increase was a main factor behind the United States decision to devalue the dollar and pressure Japan to revalue the yen—events that led quickly to the end of the Bretton Woods System of fixed exchange rates. By 1972 Japan's surplus had climbed to US$5.1 billion, 
Title: Security Treaty Between the United States and Japan
Content:  without the consent of the United States. Moreover, the accord allowed the United States to use military forces stationed in Japan without prior consultation with the Japanese government, and made no mention of any requirement for U.S. forces to defend Japan if Japan were to be attacked. Troublingly for many Japanese, the treaty had no set expiration date, nor did it specify any precise mechanism of abrogation. The accord was ratified by the US Senate on 20 March 1952 and was signed into US law by US President Harry Truman on 15 April 1952. The treaty went into effect on 28 April 1952, in conjunction with the effectuation of the Treaty of San Francisco that ended the Occupation. At the time, the United States maintained 260,000 troops on 
Title: Japan–United States relations
Content:  universities, and large corporations. In addition to making Japan more safe for free-market capitalism, the Occupation also sought to strengthen Japan's economy handing control over to American banker Joseph Dodge, who implemented a series of harsh measures to tackle inflation and limit government intervention in the economy, known collectively as the "Dodge Line." The Occupation finally came to an end in 1952 with the enactment of the San Francisco Peace Treaty, which returned sovereignty to Japan. The treaty was signed on September 8, 1951 and took effect on April 28, 1952. As a condition of ending the Occupation and restoring its sovereignty, Japan was also required to sign the U.S.-Japan Security Treaty, which brought Japan into a military alliance with the United States.

Question: when did the us stop trading with japan?
Answer: 1939.
1940.