Yellen: China Blocking Export of Minerals Used for Computer Chips Is ‘Potentially’ Retaliatory

EXCERPT:

YELLEN: "Well, I certainly expressed concern about this action, and contrasted it with the actions that we've taken. Our own actions are narrowly targeted to address national security concerns, and I — it's not clear that the actions that the Chinese took are similarly narrowly targeted at their national security concerns. So, this is an area that I expressed concern about."
BRENNAN: "Do you mean — are you suggesting there that it was just a retaliatory action?"
YELLEN: "Well, potentially."