After his seemingly miraculous victory at Agincourt, Henry attempted to use the treaty to end the Hundred Years' War in his favor. It made him "heir to France" and disinherited the French Dauphin. But when Joan of Arc succeeded in placing the Dauphin on the French throne, he repudiated the treaty and continued the war.
Subsequently, Henry VI of England's mixed English and French descent and his accession to the thrones of both nations in early infancy further destabilized the situation and prepared the ground for the Wars of the Roses. Way to nation-build, Hal.