During the French and Indian War, Britishers won the war, but it cost them and pushed them towards debt.
Explanation:
Britain forced taxes on the English colonies in America because they required the capital to get rid of war debts. The debts were getting enormous after the war so, Britishers decided to come up with an idea as they needed a way to repay the debts. Britishers determined to present acts in the colonies as they were part of the British Crown. Taxes included the Townsend Acts and the Stamp Act.
I'd think that one advantage of nationalism is the unity it builds among people who share the same nation, who start to think of each other as co-citizens. One disadvantage of nationalism is the hate can be directed against outsiders.
It was one of the reasons the US joined the war. With that, the Germans and Central Power started to lose (they had no chances after the sinking and the Zimmermann telegram)