‘I think you have no right…to demand any concession of territory from America’

In 1814, British Prime Minister Robert Jenkinson asked the Duke of Wellington to take command in Canada and win the two-year-old war against America. The duke said he would go to America, but also stated:

“I think you have no right, from the state of war, to demand any concession of territory from America... You have not been able to carry it into the enemy's territory, notwithstanding your military success, and now undoubted military superiority, and have not even cleared your own territory on the point of attack. You cannot on any principle of equality in negotiation claim a cession of territory except in exchange for other advantages which you have in your power... Then if this reasoning be true, why stipulate for the uti possidetis? You can get no territory: indeed, the state of your military operations, however creditable, does not entitle you to demand any.”

https://en.wikipedia.org/wiki/Arthur_Wellesley,_1st_Duke_of_Wellington#Waterloo_campaign

How would the victor of wars in India and battles against French armies in Portugal and Spain fared against the often disorganized American armies? Would Wellington and General Andrew Jackson faced each other in the Battle of New Orleans? And, with the victor of the not-yet-fought battle of Waterloo gone to America, who would have led the allied forces against Napoleon? For American history and British, it is good that the prime minister did not insist Wellington take command against the United States.