Netherlands is very small, so there are lot of minor cities near Rotterdam and Amsterdam. Amsterdam has Haarlem, Amstelveen and Zaandam among others. Rotterdam has The Hague, Delft, Schiedam, Capelle and Vlaardingen among other cities.
I only got Austria, I missed; Germany, United Kingdom, Italy, Netherlands, Poland, Russia, Spain, Yugoslavia, Greece, Portugal, Sweden, Ukraine, Belgium, Romania, And Hungary
Amsterdam itself has 800,000 inhabitants. It is nearly impossible there are 1.2 million people in the outskirts.
Does it count Rotterdam/The Hague together? Then it adds to 1.2 million, so under 2 million as well.