Which document issued by Austria and Prussia heightened tensions in France in August 1791?

The Declaration of Pillnitz, issued in August 1791 by Austria and Prussia, was a significant document that heightened tensions in France. This declaration expressed the desire of the two monarchies to protect the French monarchy and indicated that they were prepared to take military action if necessary. It was a response to the increasing radicalism of the French Revolution and the perceived threat it posed to monarchies across Europe.

The declaration specifically warned that if the safety of the French royal family were threatened, Austria and Prussia would intervene. This not only alarmed the revolutionary leaders in France but also increased their sense of vulnerability and urgency. The Declaration of Pillnitz is often viewed as a turning point, as it mobilized revolutionary sentiment against foreign intervention and rallied support for the revolutionary cause within France.

In contrast, the National Assembly Decree, the Letter of Louis XVI, and the Constitution of 1791 did not evoke the same level of international tension or military threat. The National Assembly Decree reflected domestic political decisions, while Louis XVI's letters primarily communicated his own struggles and intentions as a monarch. The Constitution of 1791 established the framework for a constitutional monarchy in France but did not directly involve external powers or raise alarms among other European nations in the manner that