After graduating in 1983, van Dalen enrolled in Utrecht's law school, but had to drop out in 1985 because he was constantly travelling abroad and was too busy to keep up with his studies.

[1] He became a senior policy officer for Leen van der Waal, a Member of the European Parliament for a joint RPF-GPV-SPG (Reformed Political Party) ticket in 1984.

In 1989, van Dalen joined the Ministry of Transport, Public Works and Water Management, dealing with the then-European Economic Community (EEC).

This caused the ChristianUnion – Reformed Political Party to break up, and Bas Belder joined the Europe of Freedom and Democracy grouping.

Van Dalen is a "Euro-realist" and believes that European cooperation is useful, but that the EU should not lead to a bureaucratic "superstate" involved in anything interfering with domestic social policy.