On 1 February 1793, the National Convention of Revolutionary France declared war on Great Britain and the Netherlands, expanding the list of France's enemies in the War of the First Coalition. Although British Prime Minister William Pitt the Younger had predicted fifteen years of peace one year earlier, the French declaration of war initiated nearly a quarter century of war between Britain and France with only a brief respite during the Peace of Amiens. Britain entered the war amid both a nadir in British diplomacy and internal political divisions over the direction of British foreign policy. After becoming prime minister in 1783 in the aftermath of the War of American Independence, Pitt pursued financial and naval reform to recover British strength and cautious interventionism to end Britain's diplomatic isolation in Europe. He hoped to create a collective security system based on the principles of the territorial status quo, trade agreements, neutral rights, and resolution of diplomatic disputes through mediation - armed mediation if necessary. While his domestic measures largely met with success, Pitt's foreign policy suffered from a paucity of like-minded allies, contradictions between traditional hostility to France and emergent opposition to Russian expansion, Britain's limited ability to project power on the continent, and the even more limited will of Parliament to support such interventionism. Nevertheless, Pitt's collective security goal continued to shape British strategy in the War of the First Coalition, and the same challenges continued to plague the British war effort. This led to failure in the war and left the British fighting on alone after the Treaty of Campo Formio secured peace between France and its last continental foe, Austria, on 18 October 1797.