Explanation:
For number 1: Nationalism is the identification with somebody's own nation and also to support it's interests.
For number 2: It caused intense competition among many nations with each seeking to overpower the other, a more stronger nation takes control or dominates a weaker country or territory.
For number 3: Positive incomes: promotes a sense of identity, unites people, promotes pride.
Negative incomes: leads to conflict with others, infringes on rights of others, creates xenophobia—the fear that someone will take them over.
Hope this is helpful!
It help pushed the united states into entering the war on the allied side
