Multi-speed Europe - Wikipedia, the free encyclopedia

Multi-speed Europe or two-speed Europe (called also variable geometry Europe or Core Europe depending on the form it would take in practice) is a concept that has been debated for years in European political circles, as a way to solve some institutional issues. It is currently possible for a minimum of eight EU member states to use enhanced co-operation, but this has not yet been used.

German Wikipedia dates the discussion to 2003.

The fact is that what we're experiencing right now is a top-down disaster. -Paul Krugman