For more than a decade before the crisis, EU member states had prudently required that not only commercial banking, but also investment banking subsidiaries of foreign (non-EU-based) banking organizations, be subject to Basel capital requirements in the same way as EU-based firms.
Of course, the Treaty was written with the experience of the 1970s - and the results of the academic literature that emerged in the aftermath of that unfortunate episode - in mind. First and foremost, the Treaty clarifies the objective of the ECB. The primary objective of the ECB is to maintain price stability.