Paul Methuen (diplomat) gained valuable diplomatic experience and the esteem of King Pedro. During two absences of his father he became chargé d'affaires, rising to Minister on his father's appointment as Lord Chancellor of Ireland in 1697. He was unable to prevent a Portuguese-French alliance in 1701. When his father returned to Portugal a special envoy in 1702, they were successful in breaking the alliance in 1703. The led to the Methuen commercial treaty between England and Portugal, the basis of Britain's monopoly of Portuguese trade for much of the 18th century. His father remained in Portugal as ambassador. In 1705, Methuen served
Treaty of Alliance (1778) insurance policy for France which guaranteed the support of the United States if Britain were to break the current peace they had with the French, "either by direct hostilities, or by (hindering) her commerce and navigation," as a result of the signing of the Treaty of Amity and Commerce. The treaty lays out the terms and conditions of this military alliance, establishes requirements for the signing of future peace treaties to end hostilities with the British, and provides a secret clause which leaves open the possibility of Spain and other European nations, "who may have received injuries from England," to