The bourgeoisie needs to maintain concentration flows and the US is preparing for some of the flows to be constrainee by BRICS. Europe represents a source they can extract from.
The working class in Europe is too comfortable to go to war and are more likely to demand peaceful relationships with Russia and China which will isolate the USA. Having Europe under austerity creates the conditions for larger reactionary movements that can be used by the US to fight more hot proxy conflicts in an attempt to slow down BRICS economically and an attempt to create conditions for military and political error on the part of the anti-imperialist which the USA hopes to be able to exploit to create a rapidly cascading collapse of resistance.