Why does the world have borders?

I think we have borders to keep us safe but borders also separate us and keep others put. I know after the 9/11 attack the borders were strengthened to prevent any other attacks. That's good, because they want to keep us safe right? But then the border keeps people out. What if somebody doesn't have a passport and they want to go to the United States to have a better life?The border also seperates us from other countries. The United States is sometimes considered a little better than most counries. A place you would rather live in. So if the U. S. is so nice then why can't others come in and have a better life? But separation could be good as well because if there weren't any borders there wouldn't be different countries and then there wouldn't be an organized government.

How does the U.S. benefit Mexico & how does Mexico benefit the U.S.?

Mexico benefits the United States by supplying them with workers. Though there are many illegal immigrants who find work here, they usually take the jobs Americans do not want to take. They also do not pay income tax but they do pay a sales tax which also benefits our economy.
The United States benefits Mexico by giving them jobs and also providing tourists. Though both benefit each other because of their trade partnership.
I don't know how else they benefit each other. I know there are more ways but I can't think of anything else.

How does the United States harm Mexico and how does Mexico harm the United States?

Both the United States and Mexico harm each other. I know that Mexico harms the United States when they smuggle drugs. Also when illegal immigrants cross the border it causes a problem. Another thing is that some people in the United States feel invaded by Mexico and do not take kindly to them. When Mexicans cross the border they come and find jobs because there are not as many in Mexico. They end up taking jobs other U.S. citizens could use/need. Mexico usually wants what the United States has and they can’t afford it and they turn to crime. For example drug trafficking, kidnapping, illegal immigration, etc. Another thing is that Mexico pollutes water by dumping their trash into it and it ends up washing up on U.S. shores.

But the United States harms Mexico too. When they cross the border they think that rules do not apply to them and that they can do whatever they want. It’s harder to think about how the United States harms Mexico since we usually think about how Mexico harms the U.S.

Immigration Information/Link

http://www.utexas.edu/lbj/uscir/becoming/intro.html#IMMIGRATION
This link gives information on immigration today and if you go to the homepage there is more information you can find on immigration.