Immigration can cause international problems. In this process, countries get upset with the decreasing of their population. Also, the United States can not support the people, especially with the economy so bad they just can not seem to get a job. Then, they are homeless and starve. They cause more robberies and people to get mugged for survival. Immigration can again cause international problems, which can lead to terrorists attacks, such as September 9, 2001. This is a problem leading to the e...