The 14-part ultimatum message was encrypted from Japan, the embassy had to decrypt then translate into English. To preserve secrecy the embassy didn’t employ locals, and few of the embassy staff knew English so progress was slow. The instruction to deliver the message at 1pm also didn’t mention this was absolutely critical. The Ambassador arrived at the State Department over an hour late.

Meanwhile army intelligence had decrypted and translated the message much faster, but a litany of failures meant the warning of probable attack had to be sent by telegram - not even paying for priority service - and arrived at the base after the attack.

However, it was intended to be a surprise attack, and the declaration of war was only delivered ten hours later.