Adams was originally optimistic and greatly enjoyed the city, but soon became disappointed. The Dutch, fearing British retaliation, refused to meet Adams. Before he had arrived, the British found out about secret aid the Dutch had sent to the Americans, the British authorized reprisals against their ships, which only increased their apprehension. Word had also reached Europe of American battlefield defeats. After five months of not meeting with a single Dutch official, Adams in early 1781 pronounced Amsterdam "the capital of the reign of Mammon."[120] He was finally invited to present his credentials as ambassador to the Dutch government at The Hague on April 19, 1781, but they did not promise any assistance. In the meantime, Adams thwarted an attempt by neutral European powers to mediate the war without consulting the United States.[121] In July, Adams consented to the departure of both of his sons; John Quincy went with Adams's secretary Francis Dana to Saint Petersburg as a French interpreter, in an effort to seek recognition from Russia, and a homesick Charles returned home with Adams's friend Benjamin Waterhouse.