At the end of the Spanish Succession War (1700-1714), the Treaty of Utrecht was signed as a compromise between both factions that fought in it -- Philip, Duke of Anjou (Louis XIV's grandson) was confirmed into the spanish throne, but was also obligated to renounce any future claims to the throne of France.
So, my question is: is there any way for France and Spain to end up in personal union after the treaty is signed? Such as by having Britain suffer a successful jacobite rebellion or by having France defeat Britain in a major war (especially the Seven Years' War)? I'm under the impression that the treaty had to be enforced by someone.