In 1938 the present author's thesis “De invloed van oorlog op de geldigheid van verdragen” (The effect of war on the validity of treaties) appeared. While this book was being written, there was available only one Netherlands judicial decision on the subject from the year 1709. After 1938 frequently cases came before Netherlands courts in which a decision had to be taken about the effect of war on treaties. In this paper the author examines these judicial decisions for the purpose of ascertaining whether they are in line with the results of his earlier study.
The conclusions to which the author is lead by his present investigations, may be summarized as follows:
1. Apart from one case in which a Netherlands court regarded an extradition treaty as cancelled by war and from some few judgments using ambiguous language, the prevailing trend in Netherlands case law is that war only suspends the operation of most categories of treaties.
2. Except in the cases mentioned sub 3, all Netherlands judicial decisions on the subject are in accordance with international law as it was described by the author in 1938.
3. Some decisions regarded de facto enforceable provisions of the Paris Union concerning Industrial Property and of the Hague Treaty on the Regulation of Conflicts of Laws with respect to Marriage as fully operative between the Netherlands and Germany. International law in its 1938 stage of development regarded these treaties to be merely suspended between belligerents.
4. A remarkable innovation was elaborated by the Netherlands Supreme Court by deciding that a treaty suspended by war remains suspended as far and as long as its provisions are de facto unenforceable. This decision was followed by some lower court's decisions. Presumably it is meant to meet difficulties arising out of the uncertainty resulting from the lack of a treaty of peace with Germany.
