In July 1780 he had been authorized to execute the duties previously assigned to Henry Laurens, and at the Hague was eminently successful, securing there recognition of the United States as an independent government (April 19, 1782), and negotiating both a loan and, in October 1782, a treaty of amity and commerce, the first of such treaties between the United States and foreign powers after that of February 1778 with France.
In his belief that he could ensnare the courts of London and St Petersburg into separate and proportionately disadvantageous treaties, he overreached himself.
He alone could ratify treaties of peace and alliance, and on his nomination fifty-four senators were added to the senate, which thereafter numbered one hundred and twenty members appointed by him alone.
Annoyed by Whitworth's imperturbable demeanour, he ended with these words: "You must respect treaties, then: woe to those who do not respect treaties.
His own violations of the treaties of Luneville and Amiens were overlooked; and in particular men forgot that the weakening of the Knights of St John by the recent confiscation of their lands in France and Spain, and the protracted delay of Russia and Prussia to guarantee their tenure of power in Malta, furnished England with good reasons for keeping her hold on that island.