the lack of new factory jobs in the North" was not an economic problem facing the United States at the end of the Civil War. The others were all quite serious problems.
Patriotism
companionship/friendship
a reward
The U.S and Japan are not in a war, but not at peace either. Japan is damaging the ocean bye whaling (killing whales, no other country in the world does it) over-fishing with mass nets that go for miles, and polluting. The U.S is irritated by this along with several other countries, but have not launched serious ways to stop them as of now.