From the excerpt given above, it can be inferred that HALL KNEW THAT THE GROWING OUTRAGE AMONG THE AMERICAN PUBLIC WOULD HELP BRITAIN'S CAUSE.
The British government leaders had in their possession a telegraph, which contains an information that they can use to their advantage, but they refuse to release this information on time to the right person (Wilson). In the passage given above, Hall was reminding them that it is the right time to release the information because he believed that the present situation in America will also help their cause.
