A German decision on 9 September 1915 stated that attacks were only allowed on ships that were definitely British, while neutral ships were to be treated under the Prize Law rules, and no attacks on passenger liners were to be permitted at all. A fabricated story was circulated that in some regions of Germany, schoolchildren were given a holiday to celebrate the sinking of "Lusitania". This claim was so effective that James W. Gerard, the U.S. ambassador to Germany, recounted it in his memoir of his time in Germany, "Face to Face with Kaiserism" (1918), though without substantiating its validity.