XYZ AFFAIR ( 1797-98), Franco-American diplomatic crisis that led to the undeclared naval war of 1798-1800. The XYZ affair and the ensuing undeclared naval war were much more important to the new, weak American Republic than they were to France. Nevertheless, the American imbroglio did play some role in French domestic politics and naval activities during the last three years of the eighteenth century.
The consummation of an Anglo-American agreement (Jay Treaty) in 1794 set in motion a chain of events that resulted in the undeclared naval war of 1798- 1800 and the abrogation of the Franco-American Alliance of 1778, the United States' sole alliance until 1942. By decreasing Anglo-American tensions through acceptance of British interpretations of neutrality law, the Federalist administrations ( 1793-1801) placed themselves in the anti-French camp, at least insofar as Paris was concerned. Having implicitly renounced the principle of "free ships make free goods," the United States opened the way for the seizure of its vessels trading with England. Between July 1796 and June 1797, the French were alleged to have seized more than 300 American ships. Further exacerbating relations, they refused to receive C. C. Pinckney, the minister selected to replace J. Monroe, and even ordered him out of the country. The French expected that their putative friends in the Republican faction in the United States would gain control of the government because of the failures of Federalist foreign policy. Throughout this period, Paris was ill served by agents in America--J. Fauchet, J.-P. Létombe, and P.-A. Adet--who consistently overestimated the power of the pro-French bloc and misunderstood American nationalism.
As Federalists and Republicans clashed over foreign policy, so too did French factions. Indeed, stiff criticism of the Directory's anti-American measures by a majority of the membership of the Council of Five Hundred contributed to conditions that led to the coup d'état of 18 Fructidor. For his part, C.-M. Talleyrand, who became minister of foreign relations in July 1797, hoped for a