Original sentence: 2007 marks the 50th anniversary of the Treaty of Rome which is considered to be the founding document of the European Union (EU) by some, and marks the longest period of peace on the western European mainland since Pax Romana.After the Cold War many Central and Eastern European joined or tried to join this cooperation and integration process.Now with 27 member states, the EU member states comprise about 500 million people.This integration process has chiefly been the motor for and raison d'être of the European Union (formerly the European Economic Community) and is widely attributed with being the driver and enabler of this unprecedented period of peace in Europe, although not without question
Edited sentence: 2007 marks the 50th anniversary of the Treaty of Rome which is considered to be the founding document of the European Union (EU) and marks the longest period of peace in Europe since Pax Romana.After the Cold War many Central and Eastern European joined or tried to join this integration process.Now with 27 member states, the EU represents about 500 million people.This integration process has chiefly been the motor for and raison d'être of the European Union (formerly the European Economic Community) and is widely attributed with being the driver and enabler of this unprecedented period of peace in Europe