What's the gist of this section?
Indeed, one hour after Japanese air squadrons had commenced bombing
in the American island of Oahu, the Japanese ambassador to the United
States and his colleague delivered to our Secretary of State a formal reply
to a recent American message. And while this reply stated that it seemed
useless to continue the existing diplomatic negotiations, it contained
no threat or hint of war or of armed attack.
diplomatic negotiations: when two or more countries discuss in order to
reach an agreement
Paraphrase: An hour after the Japanese started bombing in Oahu, the
Japanese ambassador delivered a reply to an earlier message that stated
that the Japanese and the United States should not continue to negotiate
with each other, but it did not mention a threat of war.