Henry Harwood was asking for Graf Spee to stay in port while Millington-Drake was trying to have her expelled. Harwood had a force outside, but he could not be certain of success and knew that more ships were on the way. Diplomatic delay would let those reinforcements arrive. For Graf Spee, the faster she could return to sea, the better her opportunity to escape. In this assessment, HMS Cumberland's arrival effectively closed that opportunity, although those aboard Graf Spee did not recognise the danger.
Notable Point · 4:58-5:55
Harwood asks diplomats to hold Graf Spee until Cumberland arrives
Harwood asked for Graf Spee to remain in Montevideo while reinforcements approached, directly opposing the ambassador's push for expulsion.