How did the US become aware of Japanese plans and how did it affect peace talks between the 2 countries?

Given that the FDIC is in charge of protecting the money in a bank in case that such bank goes info bankrupt, and that the SEC is a part of the USA government that protects the stock market and its movements, it can be assumed that this agencies are in charge of protecting the money and investments of the citizens. For example, the FDIC is allowed to protect and return up to $250.000 in case that someone is about to lose their money because the bank will go bankrupt. The SEC is the commission that will regulate any inusual behavior in the stock market that could result into a financial crisis.