Answer:
Nooooooooooooo but I wanna learn
The Magna Carta was written due to tension between the unpopular King and a group of rebel barons. It was written in Windsor, England and "it promised the protection of church rights, protection for barons from illegal imprisonment, access to swift justice, and limitations on feudal payments to the Crown, to be implemented through a council of 25 barons."
That last two and prolly the second one
Because they were fighting on their own territory and defending their home, the vietcong had greater determination than the US who were not really sure what they were there for.