Answer: The phrase "leaving only oil unrestricted" means that all other goods or materials are subject to restrictions or controls, but oil is the only item that is not. In other words, oil is the only commodity that is not subject to any limitations or regulations.
The phrase is often used in the context of trade or economic sanctions. For example, a country might impose sanctions on another country, limiting or prohibiting the trade of certain goods or materials, such as weapons, luxury goods, or electronics. However, in some cases, oil might be left unrestricted, as it is a crucial commodity that is difficult to replace or substitute.
In the given context, without further information, it is not clear what type of restrictions or controls are being referred to. However, the phrase "leaving only oil unrestricted" suggests that there may be some form of trade or economic controls in place, and that oil is exempted from these controls.
Explanation: In this context, "leaving only oil unrestricted" means that the United States government had placed export controls on most goods, except for oil. The export controls referred to in the text are likely economic restrictions or regulations designed to control the export of specific goods or materials.
The phrase suggests that the US government had decided to limit exports of machinery and vegetable fibers to other countries, presumably as a result of the escalating tensions in the Pacific region. However, it chose to keep oil exports unrestricted, which could be because oil was considered essential for the US economy, or because it was a commodity that the US government did not want to restrict in the same way as other goods.
Despite this, the US government was still considering an oil embargo against Japan. An oil embargo is a complete ban on the export of oil to a particular country or group of countries, and it is typically used as an economic sanction or as a way to pressure a country into changing its behavior. The text suggests that the US government was aware of the risks associated with imposing an oil embargo and was therefore hesitant to take this step.