The cooperation of these 2 countries would allow more diversity or various options for progress. When the Brics finally resolve how things will function they will need to follow a system of control in order to work with each other. That control system will affect the entire world. If a country isn't a part of that system then I suppose they'd need an alternative in how they trade with those countries. If the brics operates in integrity then I don' t see a reason not to be a part of that, for the US, but I'm not a geopolitical, financial expert by any means.