The implied threat in the don's peech was this : He too was opposed to drugs and he even paid his people extra not to push them the problem was no matter what he did at the end of the day, when it came to drug selling "they can't say no." In other words, the message was no Don had the power to stop his own people from being disloyal. It was purely business, and drug trafficking was going to happen no matter what. The implied theat to Vito was "get on board with this or you will be losing your street muscle." Once that was made clear, then the terms of the compromise were laid out.