The Commission is hereby empowered , under the procedure laid down in Article 4 , to take the implementing measures with regard to Article 1 , to the extent that : ( a ) the German Democratic Republic introduces into its trade with third countries the Common Customs Tariff , Community customs legislation and the other common commercial policy measures or , particularly in the cases provided for under paragraph 2 , measures ensuring that the provisions laid down by the Community with regard to third countries are not circumvented :