Daniel Hutchins' Letter to Editor regarding King John, Pope Innocent III, the Magna Carta and International Law was misleading.
First, there were many abuses of power that led the pope to place England under the Interdict. While the Magna Carta addressed some of the worst abuses by King John, it wasn't intended to be a complete list. The Magna Carta was not the only thing King John was forced to accept to end the rebellion against him. Probably the most significant was that King John was forced to create a bicameral.
Second, the French king was preparing to take advantage of the rebellion and the victories being won by the rebels by invading England. King John learned of this and offered to make England a vassal of the Papal States. The pope was not interested in acquiring vassals for the Papal States. Instead, King John was forced to negotiate an end of the rebellion and the lifting of the interdict. The Magna Carta was the treaty with the rebels and church, which ended both.
Third, reading Daniel's letter may lead readers to believe King John was the victim of an aggressive pope. In reality, King John was a merciless butcher and thief.
Fourth, even if the Treaty of Paris "gave recognition to the British Monarch 'Arch-Treasurer and Prince Elector' of the Holy Roman Empire etc.," the Holy Roman Empire no longer existed. Instead, most of the territory of the Holy Roman Empire was part of the Spanish or Habsburg empires.
The Holy Roman Empire had been divided between two brothers back in the 16th century. The brothers were the sons of the Spanish emperor, and they became the husbands of the two daughters of the Holy Roman Empire. By an agreement of the two emperors, the Holy Roman Empire was divided equally between the brothers so the two daughters would be cared for. Hostility to the division and Spaniards being placed in authority over Germans, who regarded themselves as superior to Spaniards, led to the revolt we call the Protestant reformation and war. Indeed, those hostile to the division and Spaniards in control tried to play the two brothers against each other.
There are other errors in Daniel's letter as well.